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M.A., D.Sc. OXON., HON. LL.D., F.R.S. 

Secretary of the Zoological Society of London : Corresponding Member 
of the Academy of Natural Sciences of Philadelphia 

Ifcnicfeerbocfcer press 

,7 25 



ELIE METCHNIKOFF has carried on the high purpose of the 
Pasteur Institute by devoting his genius for biological 
inquiry to the service of man. Some years ago, in a series 
of Essays which were intended to be provocative and 
educational, rather than expository, he described the direc- 
tion towards which he was pressing. I had the privilege 
of introducing these Essays to English readers under the 
title The Nature of Man, ai^tudy in Optimistic Philosophy. 
In that volume, Professor Metchnikoff recounted how 
sentient man, regarding his lot in the world, had found it 
evil. Philosophy and literature,>religion and folk-lore, in 
ancient and modern times have been deeply tinged with 
pessimism. The source of these gloomy views lies in the 
nature of man itself. Man has inherited a constitution 
from remote animal ancestors, and every part of his struc- 
ture, physical, mental and emotional, is a complex legacy 
of diverse elements. Possibly at one time each quality 
had its purpose as an adaptation to environment, but, as 
man, in the course of his evolution, and the environment 
itself have changed, the old harmonious intercourse 
between quality and circumstances has been dislocated in 
many cases. And so there have come into existence many 
instances of what the Professor calls " disharmony," per- 
sistences of structures, or habits, or desires that are no 


longer useful, but even harmful, failures of parallelism 
between the growth, maturity and decay of physical and 
mental qualities and so forth. Religions and philosophies 
alike have failed to find remedies or efficient anodynes for 
these evils of existence, and, so far, man is justified of 
his historical and actual pessimism. 

Metchnikoff, however, was able to proclaim himself an 
optimist, and found, in biological science, for the present 
generation a hope, or, at the least, an end towards which to 
work, and for future generations a possible achievement of 
that hope. Three chief evils that hang over us are disease, 
old age, and death. Modern science has already made vast 
strides towards the destruction of disease, and no one has 
more right to be listened to than a leader of the Pasteur 
Institute when he asserts his confidence that rational 
hygiene and preventive measures will ultimately rid man- 
kind of disease. The scientific investigation of old age 
shows that senility is nearly always precocious and that its 
disabilities and miseries are for the most part due to pre- 
ventable causes. Metchnikoff showed years ago that there 
exists in the human body a number of cells known gener- 
ally as phagocytes, the chief function of which is to devour 
intruding microbes. But these guardians of the body may 
turn into its deadly enemies by destroying and replacing 
the higher elements, the specific cells of the different tissues. 
The physical mechanism of senility appears to be in large 
measure the result of this process. Certain substances, 
notably the poisons of such diseases as syphilis and the 
products of intestinal putrefaction, stimulate the activity 
of the phagocytes and so encourage their encroachment on 
the higher tissues. The first business of science is to re- 
move these handicaps in favour of the wandering, cor- 
roding phagocytes. Specific poisons must be dealt with 


separately, by prevention or treatment, and it is well known 
that Metchnikoff has made great advances in that direc- 
tion. The most striking practical side of The Nature of 
Man, however, was the discussion of the cause and pre- 
vention of intestinal putrefaction. Metchnikoff believes that 
the inherited structure of the human large intestine and the 
customary diet of civilised man are specially favourable to 
the multiplication of a large number of microbes that cause 
putrefaction. The avoidance of alcohol and the rigid ex- 
clusion from diet of foods that favour putrefaction, such as 
rich meats, and of raw or badly cooked substances con- 
taining microbes, do much to remedy the evils. But the 
special introduction of the microbes which cause lactic fer- 
mentation has the effect of inhibiting putrefaction. By 
such measures Metchnikoff believes that life \vill be greatly 
prolonged and that the chief evils of senility will be 
avoided. It may take many generations before the final 
result is attained, but, in the meantime, great amelioration 
is possible. There remains the last enemy, death. Metch- 
nikoff shows that in the vast majority of cases death is not 
"natural," but comes from accidental and preventable 
causes. When diseases have been suppressed and the 
course of life regulated by scientific hygiene, it is probable 
that death would come only at an extreme old age. Metch- 
nikoff thinks that there is evidence enough at least to 
suggest that when death comes in its natural place at the 
end of the normal cycle of life, -it would be robbed of its 
terrors and be accepted as gratefully as any other part of 
the cycle of life. He thinks, in fact, that the instinct of life 
would be replaced by an instinct of death. v 

Metchnikoff's suggestion, then, was that science should 
be encouraged and helped in every possible way in its task 
of removing the diseases and habits that now prevent 


human life from running its normal course, and his belief 
is that were the task accomplished, the great causes of 
pessimism would disappear. 

In this new volume, The Prolongation of Life, the 
main thesis is carried further, and a number of criti- 
cisms and objections are met. The latter, so far as they 
relate to technical details, I need say nothing of here, as 
Metchnikoff and his staff at the Pasteur Institute are the 
most skilled existing technical experts on these matters, 
but I cannot refrain from a word of comment on the bril- 
liant treatment of the objection to the suggested ameliora- 
tion of human life that it considered only the individual 
and neglected the just subordination of the individual to 
society. In the sixth Part of this volume, Metchnikoff dis- 
cusses the relation of the individual to the species, society 
or colony, from the general point of view of comparative 
biology, and shows that as organisation progresses, the 
integrity of the individual becomes increasingly important. 
Were orthobiosis, the normal cycle of life, attained by 
human beings, there still would be room for specialisation 
of individuals and for differentiation of the functions of 
individuals in society, but instead of the specialisation and 
differentiation making individuals incomplete throughout 
their whole lives, they would be distributed over the 
different periods of the life of each individual. 

As these lines are intended to be an introduction, not a 
commentary, I will now leave the reader to follow the 
argument in the book itself. 

LONDON, August, 1907. 


IT is now four years since I wrote a volume, the English 
translation of which was called The Nature of Man, and 
which was an attempt to frame an optimistic conception of 
life. Human nature contains many very complex elements, 
due to its animal ancestry, and amongst these there are 
some disharmonies to which our misfortunes are due, but 
also elements which afford the promise of a happier human 

My views have encountered many objections, and I wish 
to reply to some of these by developing my arguments. 
This was my first task in this book, but I have also brought 
together a series of studies on problems which closely 
affect my theory. 

Although it has been possible to support my conception 
by new facts, some of which have been established by my 
fellow-workers, others by myself, there still remain many 
sides of the subject where it is necessary to fall back on 
hypotheses. I have accepted such imperfections instead of 
delaying the publication of my book. 

Even at present there are critics who regard me as in- 
capable of sane and logical reasoning. The longer I post- 
pone publication, the longer would I leave the field open 
to such persons. What I have been saying may serve also 


as a reply to the remark of one of my critics, that my ideas 
have been " suggested by self-preoccupation." 

It is, of course, quite natural that a biologist whose atten- 
tion had been aroused by noticing in his own case the 
phenomena of precocious old age should turn to study the 
causes of it. But it is equally plain that such a study could 
give no hope of resisting the decay of an organism which 
had already for many years been growing old. If the ideas 
which have come out of my work bring about some modi- 
fication in the onset of old age, the advantage can be 
gained only by those who are still young, and who will 
be at the pains to follow the new knowledge. This volume, 
in fact, like my earlier one on the "Nature of Man," is 
directed much more to the new generation than to that 
which has already been subjected to the influence of the 
factors which produce precocious old age. I think that 
thus the experience of those who have lived and worked 
for long can be made of service to others. 

As this volume is a sequel to The Nature of Man, I 
have tried as much as possible to avoid repetition of what 
was fully explained in the earlier volume. 

Here I bring together the results of work that has been 
done since the publication of The Nature of Man. Some 
of the chapters relate to subjects upon which I have lec- 
tured, or which, in a different form, have been printed 
before. For instance, the section on the psychic rudiments 
of man appeared in the Bulletin de I' Institut general psycho- 
logique of 1904, the essay on Animal Societies was pub- 
lished in the Revue Philomatique de Bordeaux et du Sud- 
Ouest of 1904, and in the Revue of J. Finot of the same 
year, whilst a German translation of it appeared in Prof. 
Ostwald's Annalen der Naturphilosophie. The chapter 
on soured milk first appeared as a pamphlet, published in 


1905. The substance of my views on natural death was 
published in June last in " Harper's Monthly Magazine" 
of New York, while the chapter on natural death in animals 
appeared in the first number of the Revue du Mois for 

I have to thank most sincerely the friends and pupils 
who have helped me by bringing before me new facts, or 
other materials; the names of these will appear in their 
proper places in the volume. I have not mentioned by 
name, however, Dr. J. Goldschmidt, whose continual en- 
couragement and practical sympathy have made my work 
much easier. 

Finally, my special thanks are due to Drs. Em. Roux 
and Burnet, and M. Mesnil, who have been so good as to 
correct my manuscript and the proofs of this volume. 

E. M. 
PARIS, Feb. 7, 1907. 








Treatment of old people in uncivilised countries. Assassination 
of old people in civilised countries. Suicide of old people. 
Public assistance in old age. Centenarians. Mme. 
Robineau, a lady of 106 years of age. Principal characters 
of old age. Examples of old mammals. Old birds and 
tortoises. Hypothesis of senile degeneration in the lower 
animals I 



Hypothesis of the causation of senility. Senility cannot be 
attributed to the cessation of the power of reproduction of 
the cells of the body. Growth of the hair and the nails in 
old age. Inner mechanism of the senescence of the tissues. 
Notwithstanding the criticisms of M. Marinesco, the 
neuronophags are true phagocytes. The whitening of hair, 
and the destruction of nerve cells as arguments against a 
theory of old age based on the failure of the reproductive 
powers of the cells ......... 15 



Action of the macrophags in destroying the higher cells. 
Senile degeneration of the muscular fibres. Atrophy of the 



skeleton. Atheroma and arterial sclerosis. Theory that 
Old Age is due to alteration in the vascular glands. 
Organic tissues that resist phagocytosis .... 25 




Relation between longevity and size. Longevity and the period 
of growth. Longevity and the doubling in weight after 
birth. Longevity and rate of reproduction. Probable rela- 
tions between longevity and the nature of the food . . 39 



Longevity in the lower animals. Instances of long life in sea- 
anemones and other vertebrates. Duration of life of insects. 
Duration of life of " cold-blooded " vertebrates. Dura- 
tion of life of birds. Duration of life of mammals. 
Inequality of the duration of life in males and females. 
Relations between longevity and fertility of the organism . 47 



Relations between longevity and the structure of the digestive 
system. The caeca in birds. The large intestine of mam- 
mals. Function of the large intestine. The intestinal 
microbes and their agency in producing auto-intoxication 
and auto-infection in the organism. Passage of microbes 
through the intestinal wall ....... 59 



Relations between longevity and the intestinal flora. Rumi- 
nants. The horse. Intestinal flora of birds. Intestinal 
flora of cursorial birds. Duration of life in cursorial 
birds. Flying mammals. Intestinal flora and longevity 
of bats. Some exceptions to the rule. Resistance of the 
lower vertebrates to certain intestinal microbes ... 73 



Longevity of man. Theory of Ebstein on the normal duration 
of human life. Instances of human longevity. Circum- 
stances which may explain the long duration of human life 84 




Theory of the immortality of unicellular organisms. Examples 
of very old trees. Examples of short-lived plants. Pro- 
longation of the life of some plants. Theory of the natural 
death of plants by exhaustion. Death of plants from auto- 
intoxication . 94 



Different origins of death in animals. Examples of natural 
death associated with violent acts. Examples of natural 
death in animals without digestive organs. Natural death 
in the two sexes. Hypothesis as to the cause of natural 
death in animals . . . . . . . . . 109 



Natural death in the aged. Analogy of natural death and 
sleep. Theories of sleep. Ponogenes. The instinct of 
sleep. The instinct of natural death. Replies to critics. 
Agreeable sensation at the approach of death . . .119 




Complaints of the shortness of our life. Theory of " medical 
selection " as a cause of degeneration of the race. Utility 
of prolonging human life .... . 132 




Ancient methods of prolonging human life. Gerokomy. The 
" immortality draught " of the Taoists. Brown-S6quard's 
method. The spermine of Poehl. Dr. Weber's precepts. 
Increased duration of life in historical times. Hygienic 
maxims. Decrease in cutaneous cancer .... 136 



Measures against infectious diseases as aiding in the prolonga- 
tion of life. Prevention of syphilis. Attempts to prepare 
serums which could strengthen the higher elements of the 
organism 145 



Uselessness of the large intestine in man. Case of a woman 
whose large intestine was inactive for six months. Another 
case where the greater part of the large intestine was com- 
pletely shut off. Attempts to disinfect the contents of the 
large intestine. Prolonged mastication as a means of pre- 
venting intestinal putrefaction 151 


The development of the intestinal flora in man. Harmlessness 
of sterilised food. Means of preventing the putrefaction of 
food. Lactic fermentation and its anti-putrescent action. 
Experiments on man and mice. Longevity in races which 
used soured milk. Comparative study of different soured 
milks. Properties of the Bulgarian Bacillus. Means of 
preventing intestinal putrefaction with the help of microbes 161 




Reply to critics who deny the simian origin of man. Actual 
existence of rudimentary organs. Reductions in the struc- 



ture of the organs of sense in man. Atrophy of Jacobson's 
organ and of the Harderian gland in the human race . . 184 



The mental character of anthropoid apes. Their muscular 
strength. Their expression of fear. The awakening of 
latent instincts of man under the influence of fear . .191 



Fear as the primary cause of hysteria. Natural somnambulism. 
Doubling of personality. Some examples of somnam- 
bulists. Analogy between somnambulism and the life of 
anthropoid apes. The psychology of crowds. Importance 
of the investigation of hysteria for the problem of the origin 
of man ........... 200 





Problem of the species in the human race. Loss of individuality 
in the associations of lower animals. Myxomycetes and 
Siphonophora. Individuality in Ascidians. Progress in the 
development of the individual living in a society . .212 



Social life of insects. Development and preservation of indi- 
viduality in colonies of insects. Division of labour and 
sacrifice of individuality in some insects .... 220 



Human societies. Differentiation in the human race. Learned 
women. Habits of a bee, Halictus quadricinctus. Col- 
lectivist theories. Criticisms by Herbert Spencer and 




Nietzsche. Progress of individuality in the societies of 
higher beings . 223 




Oriental origin of pessimism. Pessimistic poets. Byron. 

Leopardi. Poushkin. Lermontoff. Pessimism and suicide 233 



Attempts to assign reasons for the pessimistic conception of 
life. Views of E. von Hartmann. Analysis of Kowalev- 
sky's work on the psychology of pessimism .... 239 



Relation between pessimism and the state of the health. 
History of a man of science who was pessimistic when 
young and who became an optimist in old age. Optimism 
of Schopenhauer when old. Development of the sense of 
life. Development of the senses in blind people. The sense 
of obstacles 247 





Goethe's youth. Pessimism of youth. Werther. Tendency to 
suicide. Work and love. Goethe's conception of life in 
his maturity 261 



Goethe's optimistic period. His mode of life in that period. 
Influence of love in artistic production. Inclinations 
towards the arts must be regarded as secondary sexual char- 



acters. Senile love of Goethe. Relation between genius 
and the sexual activities ....... 270 



Old age of Goethe. Physical and intellectual vigour of the 
old man. Optimistic conception of life. Happiness in life 
in his last period 279 



Faust the biography of Goethe. The three monologues in 
the first Part. Faust's pessimism. The brain-fatigue 
which finds a remedy in love. The romance with Mar- 
guerite and its unhappy ending . . . . . . 283 



The second Part of Faust is in the main a description of senile 
love. Amorous passion of the old man. Humble attitude 
of the old Faust. Platonic love for Helena. The old 
Faust's conception of life. His optimism. The general idea 
of the play 290 




Difficulty of the problem of morality. Vivisection and anti-vivi- 
section. Enquiry into the possibility of rational morality. 
Utilitarian and intuitive theories of morality. Insufficiency 
of these 301 



Attempts to found morality ori the laws of human nature. 
Kant's theory of moral obligation. Some criticisms of the 
Kantian theory. Moral conduct must be guided by reason 309 




Individual morality. History of two brothers brought up in the 
same circumstances, but whose conduct was quite different. 
Late development of the sense of life. Evolution of sym- 
pathy. The sphere of egoism in moral conduct. Christian 
morality. Morality of Herbert Spencer. Danger of exalted 
altruism . 316 



Human nature must be modified according to an ideal. Com- 
parison with the modification of the constitution of plants 
and of animals. Schlanstedt rye. Burbank's plants. 
The ideal of orthobiosis. The immorality of ignorance. 
The place of hygiene in the social life. The place of altru- 
ism in moral conduct. The freedom of the theory of 
orthobiosis from metaphysics 325 






Treatment of old people in uncivilised countries Assassina- 
tion of old people in civilised countries Suicide of old people 
Public assistance in old age Centenarians Mme. 
Robineau, a lady of 106 years of age Principal characters 
of old age Examples of old mammals Old birds and tor- 
toises Hypothesis of senile degeneration in the lower 

IN the ' ' Nature of Man ' ' I laid down the outlines of a theory 
of the actual changes which take place during the sen- 
escence of our body. These ideas, on the one hand, have 
raised certain difficulties, and, on the other, have led to new 
investigations. As the study of old age is of great 
theoretical importance, and naturally is of practical value, 
I think that it is useful to pursue the subject still further. 
^. Although there exist races which solve the difficulty of 
^ old age by the simple means of destroying aged people, 
y^ the problem in civilised countries is complicated by our 
more refined feelings and by considerations of a general 

In the Melanesian Islands, old people who have become 
incapable of doing useful work are buried alive. 

In times of famine, the natives of Tierra del Fuego kill 
and eat the old women before they touch their dogs. 



When they were asked why they did this, they said that 
dogs could catch seals, whilst old women could not do so. 

Civilised races do not act like the Fuegians or other 
savages ; they neither kill nor eat the aged, but none the 
less life in old age often becomes very sad. As they are 
incapable of performing any useful function in the family 
or in the village, the old people are regarded as a heavy 
burden. Although they cannot be got rid of, their death 
is awaited with eagerness, and is never thought to come 
soon enough. The Italians say that old women have seven 
lives. According to a Bergamask tradition, old women 
have seven souls, and after that an eighth soul, quite 
a little one, and after that again half a soul ; whilst the 
Lithuanians complain that the life of an old woman is so 
tough that it cannot be crushed even in a mill. We may 
take it as an echo of such popular ideas that murders of 
old people are extremely common even in the most civilised 
European countries. I have been astonished in looking 
through criminal records to see how many cases there are 
of the murder of old people, specially of old women. It is 
easy to divine the motives of these acts. A convict of the 
Island of Saghalien, condemned for the assassination of 
several old persons, declared naively to the prison doctor : 
"Why pity them? They were already old, and would 
have died in any case in a few years." 

In the celebrated novel of Dostoiewsky, " Crime and 
Punishment," there is a tavern scene where young people 
discuss all sorts of general topics. In the middle of the 
conversation a student declares that he would " murder and 
rob any cursed old woman without the least remorse." 
" If the truth were told," he goes on to say, "this is how 
I look at the thing. On the one hand a stupid old woman, 
childish, worthless, ill-tempered, and in bad health ; no one 
would miss her, indeed she is a nuisance to evervone. She 


does not even herself know any reason why she should 
live, and perhaps to-morrow death will make a good rid- 
dance of her. On the other hand, there are fresh and 
vigorous young people who are dying in their 
thousands, in the most senseless way, no one troubling 
about them, and everywhere the same thing is going on." 

Old people not only run the risk of murder; they very 
often end their own lives prematurely by suicide. 

They prefer death to a life oppressed by material hard- 
ships or burdened by diseases. The daily papers give many 
instances of old people who, tired of suffering, asphyxiate 
themselves by their charcoal stoves. 

The frequency of suicide in the case of the old has been 
established by numerous statistics, and the new facts which 
I now cite do no more than confirm it. In 1878, in 
Prussia, amongst 100,000 individuals there were 154 cases 
of suicide of men between the ages of 20 and 50, but 295, 
that is to say, nearly twice as many of men between the 
ages of 50 and 80. In Denmark, a country in which 
suicide is notoriously common, a similar proportion exists. 
Thus, in Copenhagen, in the ten years from 1886 to 1895, 
there were 394 suicides of men between 50 and 70. These 
figures relate to 100,000 individuals. Of the suicides 
36^ per cent, were those of people in the prime of life, 
63 per cent, those of the aged. 1 

In such circumstances, it is natural that politicians and 
philanthropists have made many attempts to ameliorate the 
old age of the poor. In some countries laws have been 
passed to bring about this. For instance, a Danish law 
of June 27th, 1891, established compulsory aid for the 
aged, enacting that every person more than 60 years 
old was to have the legal right to aid if required. In 
1896 more than 36,000 people (36,246) were pensioned 

1 Westergaard, Mortalitaet u. Morbilitaet, 2nd. Edit., 190!, pp. 653-655. 

B 2 


under this law, at a cost of nearly ,200,000. In Belgium, 
the indigent old people are not pensioned until they reach 
the age of 65. In France, until recently, the aged poor 
could be supported at the public expense only by prosecut- 
ing them and sending them to prison for begging. This 
state of affairs, however, ceased with the application of the 
law of July i5th, 1905, according to which any French 
subject without resources, unable to support himself by 
work, and either more than 70 years of age, or suffering 
from some incurable infirmity or disease, is to receive 
public assistance. 

It has been thought the proper course to make such laws, 
and to lay the burden on the general population, without 
inquiring if it may not be possible to retard the debility 
of old age to such an extent that very old people might 
still be able to earn their livelihood by work. Old age 
can be studied by the methods of exact science, and there 
may yet be established some regimen by which health and 
vigour will be preserved beyond the age where now it is 
generally necessary to resort to public charity. With this 
object, a systematic investigation of senescence should be 
made in institutions for the aged, where there are always 
a large number of people from 75 to 90 years old, although 
centenarians are extremely rare. I know many institu- 
tions for aged men where, from their first foundation, there 
has been no case of an inhabitant reaching the age of 100, 
and even in similar institutions for women, although 
women live to much greater ages than men, centenarians 
are very rare. At the Salpetriere, for instance, where there 
is always a large number of old women, it is the rarest 
chance to find a centenarian. Opportunity for the study 
of the extremely aged is to be found only in private 


Most of the centenarians whom I have been able to see 
have been so defective mentally that all that can be studied 
in them are the physical qualities and functions. A few 
years ago an old woman who had reached her looth year 
was the pride of the Salpetriere. She was bedridden and 
extremely feeble physically and mentally. She replied 
briefly when she was asked questions, but apparently with- 
out any idea of what they meant. 

Not long ago, a lady who lived in a suburb of Rouen 
reached her looth birthday. The local newspapers wrote 
exaggerated articles about her, praising the integrity of her 
mind and her physical strength. I paid a visit to her 
myself, hoping to make a detailed investigation, but I 
found at once that the journalists had completely misrepre- 
sented her condition. Although her physical health was 
fairly good, her intelligence had degenerated to such an 
extent that I had to abandon the idea of any serious inves- 

The most interesting of all the centenarians with whom 
I have become acquainted had reached an extremely 
advanced age, having entered upon her loyth year. It is 
about two years ago that a journalist, Monsieur Flamans, 
took me to see this Mme. Robineau who lived in a suburb 
of Paris. I found her a very old-looking lady, rather 
short, thin, with a bent back, and leaning heavily on a 
cane when she walked. The physical condition (Mme. 
Robineau was born on January i2th, 1800), of this woman 
of more than 106 years, showed extreme decay. She had 
only one tooth ; she had to sit down after every few steps, 
but, once comfortably seated, she could remain in that 
position for quite a long time. She went to bed early and 
got up very late. Her features displayed very great age 
(see Fig. i), although her skin was not extremely wrinkled. 


FIG. i. Mme. Robineau, a centenarian. From a photograph taken on her 
one hundred and fifth birthday. 

The skin of her hands had become so transparent that one 
could see the bones, the blood-vessels, and the tendons. 
Her senses were very feeble; she could see only with one 
eye ; taste and smell were extremely rudimentary ; her hear- 


ing was her best means of relation with the external world. 
None the less, Dr. Lowenberg, a well-known aurist, had 
assured himself that her auditory organs showed in a most 
marked degree, the usual signs of old age, such as complete 
insensibility to high notes and slight deafness for low 
notes. Dr. Lowenberg attributed these changes to senile 
degeneration of the ear which affected more and more 
seriously the nervous mechanism although it had caused 
little change in the conducting apparatus. Notwithstand- 
ing her physical weakness, Mme. Robineau retained her 
intelligence fully, her mind remained delicate and refined 
and the goodness of her heart was touching. In contrast 
with the usual selfishness of old people, Mme. Robineau 
took a vivid interest in those around her. Her conversation 
was intelligent, connected, and logical. Examination of 
the physical functions of this old lady revealed facts of 
great interest. Dr. Ambard found that the sounds of the 
heart were normal, but perhaps a little accentuated. The 
pulse was regular, 70 to 84 a minute, and its tension was 
normal. The arterial pressure was 17. The lungs were 
sound. All these facts testify to her general health. The 
most remarkable circumstance was the absence of sclerosis 
of the arteries, although such degeneration is usually 
believed to be a normal character of old age. 

Analysis of the urine, made on several occasions, showed 
that the kidneys were affected with a chronic disease, 
which, however, was not serious. 1 

Although the sense of taste was weak, Madame Robineau 

1 The volume of the urine excreted in 24 hours (in January 1905) 
was 500 c.c., with a density of 1019. There was no albumen or 
sugar. The quantity, per litre, of urea was 1 1*50 gr., of chlorides 9 gr., 
of phosphates ri5 gr. The sediment contained crystals of uric acid, 
some pavement epithelium cells, a very few cells from the tubules, some 
hyaline platelets and isolated white corpuscles. 


had a fair appetite. She ate and drank little, "but her 
diet was varied. She took butcher's meat or chicken ex- 
tremely seldom, but ate eggs, fish, farinaceous food, vege- 
tables, and stewed fruit, and drank sweetened water with 
a little white wine, and sometimes, after a meal, a small 
glass of dessert wine. The processes of alimentary diges- 
tion and excretion were normal. 

It has sometimes been thought that duration of life is 
a hereditary property. There was no evidence for this 
in the present case. Madame Robineau's relatives had 
died comparatively early in life, and a centenarian was 
unknown in her family. Her great age was an acquired 
character. Her whole life had been extremely regular. 
She had married a timber merchant, and had lived for 
many years in a suburb of Paris in comfortable circum- 
stances. Her character was gentle and affectionate; she 
was thoroughly domesticated, and had been devoted to 
home life with very few distractions. 

At the age of 106 years, her intelligence suddenly became 
weak. She lost her memory almost completely, and some- 
times wandered. But her gentle and affectionate disposi- 
tion remained unaltered. 

The appearance of aged persons is too well known to 
make detailed description necessary. The skin of the face 
is dry and wrinkled and generally pale; the hairs on the 
head and the body are white; the back is bent, and the 
gait is slow and laborious, whilst the memory is weak. 
Such are the most familiar traits of old age. Baldness 
is not a special character; it often begins during youth 
and naturally is progressive, but if it has not already 
appeared, it does not come on with old age. 

The stature diminishes in old age. As the result of a 
series of observations, it has been established that a man 


loses more than an inch (3'i66 cm.), and a woman more 
than an inch and a half (4*3 cm.), between the ages of 
fifty and eighty-five years. In extreme cases, the loss 
may be nearly three inches. The weight also becomes 
less. According to Quetelet, males attain their maximum 
weights at the age of forty, females at that of fifty. From 
the age of sixty years onwards, the body becomes 
lighter, the loss at eighty being as much as thirteen 

Such losses of height and Weight are signs of the general 
atrophy of the aged organism. Not merely the soft parts, 
such as the muscles and viscera, but even the bones lose 
weight, in the latter case the loss being of the mineral 
constituents. This process of decalcification makes the 
skeleton Brittle, and is sometimes the cause of fatal acci- 

Jfre loss of muscular tissue is specially great. The 
v61ume diminishes, and the substance becomes paler; the 
fat between the fibres is absorbed, and may disappear 
completely. Movements are slower, and the muscular 
force is abated. This progressive degeneration has been 
examined by dynamometrical measurements of the hand 
and the trunk, and is greater in males than in females. 

The volumes and weights of the visceral organs simi- 
larly become smaller, but the diminution is not uniform. 

The old age of lower mammals presents characters 
similar to those found in man. I can now give other 
instances than the case of the old dog which I described 
in the " Nature of Man." 

I will first take the case of old elephants, described by 
a competent observer. "The general appearance is 
wretched, the skull being often hardly covered with skin ; 
there are deep abrasions under the eyes, and smaller ones 


on the cheeks, whilst the skin of the forehead is very* 
often deeply fissured or covered with lumps. The eyes 
are usually dim, and discharge an abnormal quantity of 
water. The margin of the ears, specially on the lower 
side, is usually frayed. The skin of the trunk is rough- 
ened, hard, and warty, so that the organ has lost much 
of its flexibility. The skin on the body generally is worn 
and wrinkled; the legs are thinner than in maturity, the 

FIG. 2. A Mare, thirty-seven years old. 

huge mass of muscles being much shrunken, whilst the 
circumference, especially just above the feet, is consider- 
ably reduced. The skin round the toe-nails is roughened 
and frayed. The tail is scaly and hard, and the tip is often 

Horses begin to grow old much sooner than elephants. 
I reproduce (Fig. 2) the photograph of a rare instance of 
longevity, a mare 37 years old, which belonged to M. 


Me"taine, in the department of Mayenne. The skin, bare 
in places, but elsewhere covered with long hairs, shows 
considerable atrophy. The general attitude reveals the 
feebleness of the whole body. Many birds, on the other 
hand, show at similar ages very slight external change, as 
may be seen from the photograph of a duck more than 25 
years old (Fig. 3) which belonged to Dr. Jean Charcot. At 
a still greater age, as may be seen occasionally in parrots, 

FIG. 3. A White Duck, which lived for more than a quarter of a century. 

the general debility of the body reveals itself in the atti- 
tude, in the condition of the feathers, and in the swelling 
of the joints. On the other hand, the oldest reptiles which 
have been observed do not differ in appearance from 
normal adults of the same species. I have in my posses- 
sion a male tortoise (Testudo mauritanica) given me by 
my friends MM. Rabaud and Caullery, and which is at 
least 86 years old. It shows no sign of old age, and in 


all respects behaves like any other individual of this 
species. More than 31 years ago it was wounded by a 
blow, the traces of which remain visible on the right side 
of the carapace (Fig. 4). In the last three years the 
tortoise lived in a garden at Montauban, along with two 
females which laid fertile eggs. The old male, although, 
as I have said, probably at least 86 years of age, was still 
sexually healthy. 

I have borrowed from the interesting volume of Prof. 
Sir E. Ray Lankester 1 the figure (Fig. 5) and de- 

FIG. 4. An Old Land-tortoise. 

scription of a giant tortoise from the island of Mauritius, 
which is probably the oldest of all living animals. It 
was brought to Mauritius from the Seychelles in 1764, 
and has lived since then in the garden of the Governor, 
and as it has thus already been 140 years in captivity, 
its age must be at least 150 years, although we have not 
exact information. Notwithstanding this, it shows no 
signs of old age. 

The examples which I have brought together show that 

1 Extinct Animals, London, 1905, pp. 28, 29. 


often amongst vertebrates there are some animals the organ- 
isms of which withstand the ravages of time much better 
than that of man. I think it a fair inference that senility, 
the precocious senescence which is one of the greatest 
sorrows of humanity, is not so profoundly seated in the 
constitution of the higher animals as has generally been 
supposed. It is not necessary, therefore, to discuss at 

FIG. 5. A Water-tortoise, mere than 150 years old. 
(After Prof. Sir E. Ray Lankester.) 

length the general question as to whether senile degenera- 
tion is an inevitable event in living organisms. 

I have already shown, in the " Nature of Man," the differ- 
ence which exists between senile degeneration in our own 
bodies and the phenomena of senescence amongst In- 
fusoria which, as M. Maupas described, are followed by 
a process of rejuvenescence. According to the more recent 
results of several investigators, the difference is still 
greater than I had supposed. Enriquez l has been able 
1 Rendiconti d. Accad. d. Lincei, 1906, vol xiv. pp. 351, 390. 


to propagate Infusoria to the 7ooth generation without any 
sign of senility being displayed. Here we are far from 
the condition in the human race. 

R. Hertwig, 1 one of the best observers of the lower 
animals, has recently attempted to show that the very 
simple animalculae of the genus Actinosphaerium are 
subject to true physiological degeneration. He has several 
times seen cultures of this Rhizopod degenerate, until all 
the individuals had died, notwithstanding the presence of 
abundant food. Prof. Hertwig attributed this to the " con- 
stitution of the Actinosphaerium having been weakened by 
too great vital activity at an earlier stage." I should have 
thought that it was a much more natural explanation to 
suppose that the culture had undergone infection by one 
of the contagious diseases which so often destroy cultures 
of different kinds of lower animals and plants. As this 
idea had not occurred to the observer, he had not searched 
for parasitic microbes amongst the granulations which are 
always present in the body of an Actinosphaerium. How- 
ever this may be, I cannot accept the facts brought forward 
by this distinguished German as a valid proof of the exist- 
ence of senile degeneration in these lowly creatures. 

The facts that I have brought together in this chapter 
justify the conclusion that human beings who reach ex- 
treme old age may preserve their mental qualities notwith- 
standing serious physical decay. Moreover, it is equally 
plain that the organism of some vertebrates is- able to 
resist the influence of time much longer than is the case 
with man under present conditions. 

1 Ueb. d. physiologische Degeneration bet Actinosphaerium eicJiJiornii. 
Jena, 1904. 



Hypothesis of the causation of senility Senility cannot be 
attributed to the cessation of the power of reproduction of 
the cells of the body Growth of the hair and the nails in 
old age Inner mechanism of the senescence of the tissues 
Notwithstanding the criticisms of M. Marinesco, the neurono- 
phags are true phagocytes The whitening of hair and 
the destruction of nerve cells, as arguments against a theory 
of old age based on the failure of the reproductive powers 
of the cells 

ALTHOUGH it has not been proved that living matter must 
inevitably undergo senile decrepitude, it is none the less 
true that man and his nearest allies generally exhibit such 
degeneration. It is therefore extremely important to recog- 
nise the real causes of our senescence. There have been 
many hypotheses on the subject, but there are compara- 
tively few definite facts known. 

Biitschli has supposed that the life of cells is maintained 
by a specific vital ferment which becomes feebler in pro- 
portion to the extent of cellular reproduction, but I cannot 
regard this as more than a pious opinion. The ferment 
has never been seen, and we do not know of its actual 
existence. According to the better-known theory of Prof. 
Weismann, old age depends on a limitation in the power 
of cells to reproduce, so that a time comes when the body 
can no longer replace the wastage of cells which is an 


inevitable accompaniment of life. As old age appears at 
different times in different species and different indivi- 
duals, Weismann has concluded that the possible number 
of cell generations differs in different cases. He has not 
found, however, a solution of the problem as to why multi- 
plication of cells should cease in one individual, whereas 
it proceeds much further in other individuals. Prof. 
Minot, 1 the American zoologist, has developed a similar 
theory, and has employed an exact method to determine 
the gradual diminution in the rate of growth of an animal 
from its birth onwards. According to him, the power 
of reproduction of the cells weakens progressively during 
life, until a point is necessarily reached at which the 
organism, no longer capable of repairing itself, begins 
to atrophy and degenerate. Dr. Buehler 2 has recently laid 
stress upon this theory. 

There is no doubt that cells reproduce much more actively 
during the embryonic period. The process becomes slower 
later on, but, none the less, continues to display itself 
throughout the whole period of life. Buehler attributes 
the difficulty with which certain wounds heal in the case 
of old people to the insufficiency of cellular reproduc- 
tion. He thinks in particular that the proliferation of the 
cells of the skin, to replace those which are worn off from 
the surface, becomes less active with age. According to 
him, it is theoretically obvious that a time must come 
when the replacement of the epidermic cells completely 
ceases. As the superficial layers of the skin continue to 
dry up and be cast off, it is plain that the epidermis must 
disappear completely. Buehler thinks that there must be 

1 "Senescence and Rejuvenation," Journal of Physiology^ 1891, 
t. xii. 

2 Biologisches Centralblatt, 1904, pp. 65, 8 1, 113. 


a similar fate for the genital glands, the muscles, and all 
the other organs. 

These theoretical considerations, however, are not com- 
patible with certain well-known facts indicating that there 
is no general cessation of the power of cell reproduction 
in old age. The hairs and the nails, which are epidermic 
outgrowths, continue to grow throughout life, their growth 
being due to the proliferation of their constituent cells. 
There is no sign of any arrest in the development of these 
structures, even in the most advanced old age. The reverse 
is true. It is well known that the hairs on some parts 
of the body increase in number and in length in old people. 
In some lower races, for instance in the Mongols, the 
moustache and the beard grow vigorously in old age, 
whilst young people of the same race have only very small 
moustaches and practically no trace of beard. So also 
in white women the fine and almost invisible down which 
covers the upper lip, the chin, and the cheeks in the young 
may become replaced by long hairs which form a mous- 
tache or beard. 

Dr. Pohl, a specialist in the growth of hair, has measured 
the rate of growth in different circumstances. He has 
shown that in an old man of 61 the hair on the temple 
grew ii mm. in a month; on the other hand, the hair on 
the same region in boys of n to 15 years old grew in the 
same time only from 11 to 12 mm. Plainly, there is no 
case here of a progressive diminution of cell-proliferation 
with age. The same observer, it is true, has shown that 
the hair of young men of between 21 and 24 years grew at 
the rate of 15 mm. a month, whilst in the same individuals, 
at the age of 61 years, the rate of growth was only 1 1 mm. ; 
but this diminution in the rate of growth is only apparent. 
The first figure concerned the hair taken from different 



regions of the scalp, whilst the second related only to the 
hair on the temples, and Dr. Pohl himself has shown that, 
in the latter region, the hair grows slower than in other 
regions. Moreover, in many boys of 11 to 15 years old, 
studied by this observer, the rate of growth was always 
less than 15 mm., and often less even than the 11 mm. 
recorded in the old man of 61. 

I have been able to note that the nails grow even in very 
old people. In the case of Mme. Robineau, the centena- 
rian, the nail of the middle ringer of the left hand grew 
2\ mm. in three weeks. In the case of a lady of 32 years 
old, the corresponding nail grew 3 mm. in two weeks, the 
difference being out of all proportion to the enormous 
difference in the age. The centenarian's nails had to be 
cut from time to time. 

Although the hairs of old people grow, they become 
white, which is a phenomenon of senile degeneration. 
Although they increase in length, the colouring matter in 
them becomes reduced and finally disappears. In the 
" Nature of Man " I described the process by which this 
blanching takes place, and which may now be regarded as 
definitely proved. It is useful as a means of interpreting 
the real nature of the process of senescence. In several 
published works, I have explained my belief that just as 
the pigment of the hair is destroyed by phagocytes, so also 
the atrophy of other organs of the body, in old age, is very 
frequently due to the action of devouring cells which I 
have called macrophags. These are the phagocytes that 
destroy the higher elements of the body, such as the nervous 
and muscular cells, and the cells of the liver and kidneys. 
This part of my theory has encountered very strong criti- 
cism, especially with regard to the part played by the 
macrophags in the senescence of nervous tissue. 


Neurologists in particular, have criticised my interpreta- 
tion. For several years M. Marinesco 1 has attacked my 
theory of the atrophy of the nerve-cells in old age. In the 
first place, he has stated that in old people, and even if 
these are very old, it is rare to find phagocytes surrounding 
and devouring the cells of the brain. In support of this 
contention, he has been good enough to send me two pre- 
parations made from the brains of two very old persons. 
After careful examination I was convinced that my oppo- 
nent had been inexact. In the brain of the two centenarians 
(one of whom died at the age of 1 17 years) there were very 
many nerve-cells surrounded by phagocytes and in process 
of being destroyed by them. It happened, however, that 
as the sections were very weakly stained, it was more diffi- 
cult to observe the facts than in the preparations upon 
which I had made my own observations. I have already 
recorded this fact in the second and third French editions 
of the " Nature of Man." 

Without taking notice of my reply, M. Marinesco has 
published another criticism of my theory in an article' 2 
entitled " Histological Investigations into the Mechanism of 
Senility." In that work, although he himself had invented 
the designation " neuronophag " for a phagocyte that 
devours nerve-cells, he denies the existence of such a power. 
He thinks that nerve-cells atrophy independently of the 
cells that surround them. The latter, the so-called neur- 
onophags, only contribute to the atrophy inasmuch as they 
press against the nerve-cells and deprive them of nutrition. 
He is confident that the constituent parts of nerve-cells are 
never found in the neuronophags. There is no question qf 

1 Com+tcs rendus de TAcadtmie des sciences, 23 April, 1900. 

2 Revue generate des sciences, 30 Dec., 1904, p. 1116. 

C 2 


phagocytosis, of the existence of cells that devour their 

M. Leri has taken a similar view in a Report on the 
Senile Brain 1 presented to a recent congress of alienists 
and neurologists. According to him " the nuclei which 
surround some of the atrophying nerve-cells do not play 
the part of neuronophags." In his monograph " La 
Neuronophagie," 2 M. Sand elaborates the same view. He 
relies on his observation that " neuronophags are usually 
either devoid of protoplasm or display only a very thin layer 
of it. They never exhibit protoplasmic outgrowths, and 
they never have granules in their cellular bodies (p. 86)." 
Still more recently MM. Laignel-Lavastine and Voisin a 
have taken the same view, maintaining that the neurono- 
phags do not display phagocytosis. 

Although I cannot undertake here to give a detailed reply 
to the arguments of my critics, I may point out a fallacy 
that vitiates their reasoning. The study of the intimate 
structure of nervous tissue involves the treatment of that 
very delicate substance by numerous active reagents. It is 
extremely important not to forget the possibility of altera- 
tions which may be produced in the processes of preparation 
and which are extremely difficult to avoid. A glance at the 
figures given by my critics shows me that the neurono- 
phags in their preparations had been subjected to violent 
treatment. When M. Leri speaks of "the nuclei which 
surround some of the nerve-cells," and M. Sand of " cells 
without protoplasm," it is clear that they had been observ- 
ing cells destroyed by the processes of the laboratory. The 

1 Le Bulletin mtdical, 1906, p. 721 ; Le Cerveau senile, Lille, 1906, 
pp. 64-69. 

- Mtmoires couronnes publics par FAcadtmie royale de Belgique, 
Bruxelles, 1906. 

3 Revue de Medecine, Nov., 1906, p. 870. 


illustrations in the memoir of M. Marinesco show that in 
his preparations, too, the neuronophags had been very 
greatly altered. 

It is well known that nuclei do not exist free in tissues, 
and that when they appear devoid of protoplasm, there has 
been some defect in the technical methods of preparing 
them for examination. As a matter of fact, neuronophags 
do not consist of nuclei with at the most a pellicle of proto- 
plasm ; like other cells, they have protoplasmic bodies 
which, however, are frequently destroyed by the violent 
processes of histological preparation. 

The arguments of my critics recall to me the words of a 
medical student, who, on being asked to describe the 
microbe of tuberculosis, said that it was a little red bacillus. 
The bacillus in question, like most bacilli, is colourless, 
but it is usual to stain it so that it may be visible under 
the microscope. The student, knowing it only in particu- 
lar preparations, had a false idea of its appearance. 

In well-made preparations, neuronophags are typical cells 
with abundant protoplasm. When they have been pre- 
served by a process that does not dissolve their contents, 
they show granules like those found in nerve-cells. 

To study neuronophagy, M. Manouelian, 1 in the labora^ 
tory of the Pasteur Institute in Paris, set himself to improve 
the technical methods of preparation. He succeeded in 
showing first that in the destruction of nerve-cells that 
occurs in cases of hydrophobia, the contents of these cells 
are absorbed by the surrounding neuronophags. " My 
observations on the cerebro-spinal ganglia of human cases 
of hydrophobia," he wrote, " show clearly that the macro- 
phags act as phagocytes of the nerve-cells." " Most of the 
cells in the nerve-ganglia contain yellow, brown, and black 
1 Annales de flnstitut Pasteur ; Oct. 1906, p. 859. 


pigmented granules, usually united in small masses. What 
becomes of these granulations on the destruction and dis- 
appearance of the nerve-cell? If, as M. Marinesco has it, 
there is no phagocytosis by the surrounding cells, but 
merely a mechanical interference, then the granules, on the 
destruction of the nerve-cells that contained them, should 
be found lying in the interstitial tissue. But this does not 
happen. The granules are ingested by cells which are true 

By the aid of a very delicate mode of preparation, M. 
Manouelian has shown that in the case of senile brains 
the granules of the nerve-cells are absorbed by neurono- 
phags. I have myself studied M. Manouelian's prepara- 
tions and can testify to the accuracy of his observations 
(Figs. 6 and 7). 

Doubt is no longer possible. In senile degeneration the 
nerve-cells are surrounded by neuronophags which absorb 
their contents and bring about more or less complete 
atrophy. It has been supposed that in order to devour their 
contents, the neuronophags must penetrate the nerve-cells, 
and such an event has rarely been seen. But it is well 
known, the phagocytosis of red blood corpuscles being a 
typical instance, that to absorb a cell a phagocyte does not 
necessarily engulf it bodily or penetrate it, but may gradu- 
ally denude it of its contents merely by resting in contact 
with it. 

There has been some discussion as to the condition of 
nerve-cells which are on the point of being devoured by 
neuronophags. It has been noticed that such cells may 
display a considerable amount of degeneration without 
being devoured, whilst, on the other hand, cells apparently 
normal have been found undergoing phagocytosis. As I 
cannot state definitely what are the conditions that induce 


the phagocytosis of nerve-cells, I shall not attempt a dis- 
cussion of the problem. 

Although the destruction of nerve-cells by neuronophags 
is a general occurrence in senile brains, one may conceive 
of cases where this does not occur. And so, in old people 
who have preserved their faculties, it may well be that the 
neuronophags have refrained from attacking the nerve-cells. 

FIG. 6. 

FIG. 7. 

FIGS. 6. & 7. Two nerve-cells from the cortex of the brain of an old dog aged 

fifteen years. 

The neuronophags surrounding the nerve-cells contain numerous granulations. 
(From preparations made by M. Manouelian.) 

But as such instances are rare, so also phagocytosis is 
usually found in senile brains, and I cannot accept M. 
Sand's denial of its existence, based on his study of two 

The general result of my investigation into the criticisms 
that have been published on this matter has confirmed me 
in my belief that neuronophagy plays a most important 


part in senescence, and recent observations that I have 
made with M. Weinberg have completely supported this 

The bleaching of hair and the atrophy of the brain in 
old age thus furnish important arguments against the view 
that senescence is the result of arrest of the reproduc- 
tive powers of cells. Hairs grow old and become white 
without ceasing to grow. The cessation of the power of 
reproduction cannot be the cause of the senescence of brain- 
cells, for these cells do not reproduce even in youth. 



Action of the macrophags in destroying the higher cells 
Senile degeneration of muscular fibres Atrophy of the skele- 
ton Atheroma and arterial sclerosis Theory that old age is 
due to alteration in the vascular glands Organic tissues 
that resist phagocytosis 

THE instances which I have selected in attempting to 
describe the mechanism of senescence of the tissues are not 
the only cases in which the importance of phagocytosis is 
evident. The blanching of hair is due to the destructive 
agency of chromophags; in atrophy of the brain neur- 
onophags destroy the higher nerve-cells. In addition to 
these instances of phagocytosis, in which the active agents 
belong to the category of macrophags, there are many other 
devouring cells, adrift in the tissues of the aged, and ready 
to cause destruction of other cells of the higher type. The 
phagocytic action is not so manifest as in the case of infec- 
tious diseases, partly because it is the method of macro- 
phags to absorb the contents of the higher cells extremely 
slowly. The mode of action is well seen in the atrophy of 
an egg-cell (Fig. 8), where the surrounding macrophags 
gradually seize hold of the granules within it and carry 
these off. As the process goes on, the ovum becomes 
reduced to a shapeless mass, and finally leaves only a few 


fragments, or disappears completely. M. Matchinsky l has 
studied the series of events in my laboratory, and I am 
myself well assured of the importance of the action of 
macrophags in the atrophy of the ovary. 

The phenomena of atrophy in general and of senile decay 
afford other cases of tissue destruction in which the phago- 

FIG. 8. Ovum of a Bitch in process of destruction by Phagocytes, which are full 

of fatty granules. 
(After M. Matchinsky.) 

cytic character of the process is more modified and obscure 
than in nerve-cells and ova. 

It is well known that progressive muscular debility is an 
accompaniment of old age. Physical work is seldom given 
to men over sixty years of age, as it is notorious that they 
are less capable of it. Their muscular movements are 
feebler and soon bring on fatigue ; their actions are slow 
and painful. Even old men whose mental vigour is un- 
impaired admit their muscular weakness. The physical 
1 Annales de FInstitut Pasteur, 1900, vol. xiv. p. 113. 


correlate of this condition is an actual atrophy of the 
muscles, and has for long been known to observers. More 
than half a century ago, Kolliker, 1 one of the founders of 
histology, devoted some attention to this matter, and 
described the senile modification of muscular tissue in the 
following words : " In old age there is a true atrophy of 
the muscles. The fibres are much more slender ; there are 
deposited in their substance numerous yellow or brown 
granules and many globular nuclei. These nuclei are fre- 
quently arranged in longitudinal series and present such 
signs of active division as are found in embryonic tissue." 

Other investigators afterwards made similar observations. 
Vulpian 3 and Douaud 3 have stated that a multiplication of 
nuclei takes places in the atrophying muscles of the old. 

As the senile degeneration of muscular tissue appeared to 
be important in my study of the mechanism of senescence, 
M. Weinberg and I examined several qtases of muscular 
atrophy in old human beings and lower animals. We were 
able to recognise the phenomena observed by our prede- 
cessors. In senile atrophy the muscular fibres contain 
many nuclei, and these, increasing rapidly, bring about an 
almost complete disappearance of the contractile substance 
(Fig. 9). The fibres preserve their striation for a certain 
time but eventually lose it and appear to contain an amor- 
phous mass with numerous, rapidly multiplying nuclei. 

The investigators who had recorded these facts thought 
of them only as curious. It is plain, in the first place, 
however, that this remarkable and rapid multiplication is a 
proof that senile atrophy is not due to failure of cell pro- 

1 Elements (fhistologie humaine, French translation, 1856, p. 222. 

2 Lemons sur la physiologie du systeme nerveux, 1 866. 

3 De la degentrescence graisseuse des muscles chez des vieillards. 
Paris, 1867. 



liferation, although the latter has frequently been suggested 
as the mechanism of senescence. In muscular atrophy, cell- 
multiplication, so far from failing, greatly increases. We 
may add muscular atrophy to the blanching of hair and the 
decay of nerve-cells as another instance showing that senile 
degeneration is not the result of cells ceasing to be able to 

FIG. 9. Degeneration of striated muscle Fibres from the auricular muscle of a 

man aged 87 years. 
(From a preparation made by Dr. Weinberg. ) 

multiply. Just as in the atrophy of the brain there is an 
increase in the volume of neurogloea, the substance in which 
the neuronophags are found, so also in the atrophy of the 
muscles there is an increase of muscular nuclei. Along 
with the increase of nuclei, however, there is an increase of 
the protoplasmic substance of the fibres known as sarco- 
plasm. The latter replaces the myoplasm, the specific 
striated substance of muscles, by a process which must be 


regarded as parallel with phagocytosis. In a normal muscle 
the two substances and the sarcoplasmic nuclei are in 
equilibrium, but in old age the sarcoplasm and its nuclei 
increase at the expense of the myoplasm. The equilibrium 
is destroyed with the result that the muscular power is 
weakened. In these conditions the sarcoplasm acts phago- 
cytically with regard to the myoplasm, just as the chromo- 
phag becomes the phagocyte of the pigment of the hair, 
or the neuronophag devours the nerve-cell. 

The investigation of other cases of muscular atrophy, as, 
for instance, that of the caudal muscles of frog-tadpoles, 
confirms the significance of the process that I have observed 
in old age. In the two cases, what takes place is the 
destruction of the contractile material of the muscles by 
myophags, a special kind of phagocyte. 

It is one of the curiosities of senile atrophy that whilst 
there is hardening or sclerosis of so many organs, the skele- 
ton, the most solid part of our frame-work, becomes less 
dense, so that the bones are friable, the condition often 
leading to serious accidents in old people. The bones 
become porous, and lose weight. It is difficult to believe 
that macrophags, although they destroy softer elements 
such as nerve-cells or muscle fibres, can be able to gnaw 
through a hard material like bone impregnated with 
mineral salts. As a matter of fact, the mechanism of bone 
atrophy must be placed in a different category from the 
phagocytosis of other organs. It is brought about, how- 
ever, by the agency of cells very like some of the macro- 
phags. These cells contain many nuclei, and are known 
as osteoclasts. They form round about the bony lamellae 
and lead to their destruction, but are incapable of breaking 
off fragments of bone and dissolving them in their interiors. 
Although the intimate mechanism of this destructive action 


is not thoroughly understood, it seems probable that the 
cells secrete some acid which softens bone by dissolving 
the lime salts. The process can be observed in the different 
varieties of caries of the bone, and in the bony atrophy of 
old age as is represented in Fig. 10. 

By the action of the osteoclasts, which themselves are 
macrophags, part of the lime in the skeleton is dissolved 
during old age and passes into the general circulation. 
This is probably a source of the lime which is deposited 
so readily in the different tissues of old people. Whilst the 
bones become lighter, the cartilages become bony, the inter- 

FlG. io. Destruction by osteoclasts of bony matter in the sternum of a man aged 

8 1 years. 
(From a preparation made by Dr. Weinberg.) 

vertebrate discs in particular becoming impregnated with 
salts, so that the well-known senile malformation of the 
backbone is produced. 

As a result of this displacement of lime in old age, the 
blood-vessels become modified in a distinctive fashion. 
Atheroma of the arteries is not invariable in old people, but 
it occurs extremely frequently. In this form of degenera- 
tion, lime salts are deposited in the walls of the cells, so that 
they become hard and friable. Several others, among 
whom I may mention Durand-Fardel and Sauvage, have 
laid stress on the coincidence of atheromatous lesions of the 
arteries and senile degeneration of the bones. The relations 


between the two alterations are very evident in the skull ; 
the meningeal artery becomes sinuous and atheromatous, 
and the grooves on the inner side of the bones of the skull in 
which it runs, flatten out, and become larger because of 
other malformations. 1 

There is no disharmony in the nature of old people so 
striking as this transference of the lime salts from the 
skeleton to the blood-vessels, producing as it does a danger- 
ous softening of the former, and a hardening of the latter 
that interferes with their function of carrying nutrition to 
the organs. It is the manifestation of an extraordinary 
disturbance of the properties of the cells that compose the 
body. The atheromatous condition of the arteries is closely 
linked with arterial sclerosis, an affection which is very 
common, although not constant, in the aged. The whole 
question of these vascular alterations is extremely complex, 
and before it can be cleared up, a number of special inves- 
tigations must be made. 

Probably diseases of the arteries of different kinds, and 
arising from different causes, are grouped under the terms 
atheroma and sclerosis. In some cases the lesions are in- 
flammatory and are due to the poisons of microbes. An 
example of such an origin is the case of syphilitic sclerosis, 
in which the specific microbes (spirilla of Schaudinn) lead 
to precocious senescence. In other cases the arteries show 
phenomena of degeneration resulting in the formation of 
calcareous platelets which interfere with the circulation of 
the blood. 

Investigations which have been made in recent years 

have led to very interesting results concerning the origin 

of atheroma of the arteries. In most cases, attempts to 

produce such lesions of the arteries by experimental 

1 Demange, tude sur la vieillesse, 1886, p. 1 18. 


methods have not succeeded, but M. Josue" 1 has been able 
to produce true arterial atheroma in rabbits by injecting 
into them adrenaline, the secretion of the suprarenal cap- 

This experiment has been repeated many times and is 
now well known. Later on, M. Boveri 2 obtained a similar 
result by injecting nicotine, the poison of tobacco. It is 
obvious, therefore, that amongst the arterial diseases which 
play so great a part in senescence, some are chronic inflam- 
mations produced by microbes, whilst others are brought 
about by poisons introduced from without. 

It is easy to understand, therefore, why these diseases of 
the arteries are not always present in old age, although 
they are very common. 

The part played by the secretion of the suprarenal glands 
in the production of arterial disease has brought renewed 
attention to a theory which supposed that certain glandular 
organs in the body play a preponderating part in senile 
degeneration. Dr. Lorand 3 in particular has argued that 
" senility is a morbid process due to the degeneration of the 
thyroid gland and of other ductless glands which normally 
regulate the nutrition of the body." It has long been 
noticed that persons affected with myxodema, as a result 
of the degeneration of the thyroid gland, look like very old 
people. Everyone who has seen the cretins in Savoy, 
Switzerland, or the Tyrol, must have noticed the aged 
appearance of these victims, although very often they are 
quite young. The condition of cretinism, with its pro- 
found bodily changes, is the result of degeneration of the 
thyroid gland. On the other hand, it is well known that 

1 C. fi. de la Socie'te' de Biologic, 14 November, 1903. 

2 Clinica medica, 1905, n. 6. 

3 Bulletins de la Sotiete royale des sciences-medicales de Bruxelles, 1905, 
n. 4, p. 105. 


in old people the thyroid and the suprarenals frequently 
show cystic degeneration. It is quite probable, therefore, 
that these so-called vascular glands have their share in 
producing senility. Many facts show that they destroy 
certain poisons which have entered the body, and it is easy 
to see that, if they have become functionless, the tissues 
are threatened with poisoning. It does not follow, how- 
ever, that their action in producing senility is exclusive, or 
even preponderating. M. Weinberg, at the Pasteur Insti- 
tute, made special investigations on this point, and found 
that the thyroid gland and the suprarenal capsules were 
almost invariably normal in old animals (cat, dog, horse), 
although the latter showed unmistakable signs of senility. 
Similarly in an old man of 80 years, who died from pneu- 
monia, the thyroid gland was quite normal. 

It must not be forgotten that the aged very often die 
from infectious diseases such as pneumonia, tuberculosis, 
and erysipelas. In these diseases the vascular glands 
generally, and the thyroid gland in particular, are very 
often affected, with the .result that what is due to infection 
has been set down as a symptom of old age. 1 

Although the appearance of patients from whom the 
thyroid gland has been removed, or in whom it has degene- 
rated spontaneously, recalls that of old people, it is possible 
to exaggerate the similarity. In the masterly accounts of 
such unfortunates, recently compiled by the well-known 
surgeon Kocher 2 there are many points which are char- 
acteristic, without being typical, of old people. 

Oedema of the skin which characterises thyroid patients 

1 Sarbach, Mittheilungen a. d. Grenzqeb. d. Med. u. CAir., vol. xv.' 

2 Verhandlungen d. Kongr. f. innere Medicin. Wiesbaden, 1906, pp. 
59, 98- 



is by no means usual in old age. The loss of hair, normal 
in the patients, is not a character of old age. In myx- 
edematous women, menstruation is very active; it ceases 
in old women. The great muscular development of 
myxedematous patients distinguishes them from old people. 

Physiological investigation does not support the exist- 
ence of any strong affinity between old age and affection 
of the thyroid gland. It is known that removal of the 
thyroid is followed by cachexia only in young subjects^ 
MM. Bourneville and Bricon l having shown that the 
tendency to cachexia after extirpation of the thyroid ceases 
almost abruptly at the age of thirty. That age may be 
taken as the limit of youth, of the time when growth is 
vigorous and the function of the thyroid most active. Cases 
of cachexia, where the thyroid gland has been removed in 
old persons from fifty to seventy, are very .rare. 

Rodents (rats, rabbits) support the removal of the thyroid 
extremely well, without signs of cachexia, although these 
are normally short-lived creatures. According to Horsley 2 
extirpation of the thyroid is not followed by cachexia in 
birds or rodents and is followed by it only very slowly in 
ruminants and horses ; it produces the condition invariably 
but slightly in man and monkeys and extremely seriously 
in carnivora. If this series be compared with the informa- 
tion given in the next section of this volume on the relative 
ages which the animals in question attain, it will be seen 
that there is no correspondence. 

In short, whilst I do not deny that the vascular glands 
may take a share in the causation of senility, in so far as 

1 Archives de Neurologie, 1886. 

2 Die Function d. Schilddruse, Virchou/s Festschrift, vol. i. 1891, 
p. 369. 


they are destroyers of poisons, I cannot agree with the 
theory of Dr. Lorand. 

I think it indubitable that in senescence the most active 
factor is some alteration in the higher cells of the body, 
accompanied by a destruction of these by macrophags 
which gradually usurp the places of the higher elements and 
replace them by fibrous tissue. Such a process affects the 
organs of secretion (kidneys), the reproductive organs, and 
in a modified form the skin, the mucous membranes, and 
the skeleton. The testes are amongst the organs which 
resist invasion by macrophags. 
I have already given an ex- 
ample (" The Nature of Man," 
p. 98) of an old man of 94 in 
whom active spermatozoa were 
produced. I know of a similar 
case, the age being 103 years. 
Such cases are not rare, and not 
only in old men, but in old 
animals, the testes continue to FIG. n. Testis tissue from a dog 

aged twenty-two years. 
be active. Dr. Wemberg and (From a preparation made by Dr. 

I have investigated these Weinberg.) 

organs in a dog which died at the age of 22 years after 
several years of pronounced senility. Many of the organs 
of the animal exhibited serious invasions by macrophags 
but the testes were extremely active, the cells being in 
free proliferation and producing abundant spermatozoa 
(Fig. 11). In harmony with this condition of the 
sexual organs, the sexual instincts of the animal remained 
normal. We have investigated another dog which died 
at the age of eighteen years. In this case the testes were 
cancerous and there was no possibility of the production of 
spermatozoa. None the less, this dog although markedly 

D 2 


senile (Fig. 12) still showed sexual instincts until shortly 
before it died. 

It is manifest that the tissues do not invariably degene- 
rate in old age, nor do all the organs that are modified in 
old age show destruction by phagocytes and replacement 
by connective tissue. Organs which produce phagocytes, 
such as the spleen, the spinal marrow and the lymphatic 
glands, certainly show traces in old age of fibrous degenera- 

FIG. 12. An old dog, iged eighteen years. 

tion but remain sufficiently active to produce macrophags 
which destroy the higher cellular elements of the body. I 
have frequently noticed cell division in such organs, and 
as an example inay give the case of the bone marrow taken 
from a man of 81 years (Fig. 13). 

The eye is an organ that is modified in old age without 
the action of macrophags. Cataract and the senile arc 
which appears as a milky ring at the edge of the cornea 


are frequent in old age. These modifications are due to 
impregnation of the parts affected by fatty matter which 
makes them opaque. This deposition of fat 1 has been 
attributed to defective nutrition. In most organs such 
fatty degeneration is followed by phagocytosis, but the 
cornea and the crystalline lens are exempt from this conse- 
quence for anatomical reasons. Most organs possess in 
addition to their higher elements a constant source of 
macrophags. Such a source of phagocytosis is the neuro- 
glcea in nervous tissues, the A 

sarcoplasm in muscular tis- 
sues ; the bones contain osteo- 
clasts and the liver and the 
kidneys are readily invaded by 
phagocytes from the blood. 
The lens and the cornea have 
no cells that are able to become 
macrophags. FlG I3< _ Bone marrow from the 

Some infectious diseases sternum of a man aged eighty- 

one years. 

bring about precocious SCnil- (From a preparation made by Dr. 
ity. A syphilitic child is "a Weinberg.) 

miniature old man, with wrinkled face, skin dull 
and discoloured and flabby and hanging in folds as 
if it were too large." 2 In such a case the active 
agent is the microbe of syphilis which has poisoned 
the child on the breast of its mother. It is no mere analogy 
to suppose that human senescence is the result of a slow but 
chronic poisoning of the organism. Such poisons, if not 
completely destroyed or eliminated, weaken the tissues, the 
functions of which become altered or enfeebled, so that, 

1 Fuss, Der Greisenbogen, in Virchotv's Archi-v, 1905, vol. clxxxii. p. 
407 ; S. Toufesco, Sur le cristallin, Paris, 1906. 

2 Edmond Fournier, Stigmates dystrophiques de PhMdosyphilis, Paris, 
1898, p. 4. * 


amongst other changes, there is deposition of fatty matter. 
The phagocytes resist the influence of invading poisons 
better than any of the other cells of the body and some- 
times are stimulated by them. The general result of 
such conditions is that there comes to be a struggle between 
the higher cells and the phagocytes in which the latter have 
the advantage. 

The answer to the question as to whether our senescence 
can be ameliorated must be approached from several points 
of view. This course I shall now follow. 





Relation between longevity and size Longevity and the 
period of growth Longevity and the doubling in weight 
after birth Longevity and rate of reproduction Probable 
relation between longevity and the nature of the food 

THE duration of the life of animals varies within very 
wide limits. Some, as for instance, the males of certain 
wheel animalculae (Rotifera) complete their cycle of life 
from birth to death in 50 or 60 hours, whilst others, like 
some reptiles, live more than 100 years, and quite possibly 
may live for two or three centuries. 

Enquiry has been made for many years as to whether 
there are laws governing these different durations of life. 
Even the most casual observation of domesticated animals 
has shown that, as a general rule, small animals do not 
live so long as large ones ; mice, guinea pigs, and rabbits 
for instance, have shorter lives than geese, ducks, and 
sheep, whilst these again are survived by horses, deer, 
and camels. Of all the mammals which have lived under 
the protection of man, the elephant is at once the largest, 
and the most long-lived. 

However, it is not difficult to show that there is no 
absolute relation between size and longevity,' since parrots, 
ravens, and geese live much longer than many mammals, 
and than some much larger birds. 


As a general rule it may be said that a large animal takes 
more time than a small one to reach maturity, and it has 
been inferred from this that the length of the periods of 
gestation and of growth were in proportion to the longe- 
vity. Buffon 1 long ago stated his opinion that the " total 
duration of life bore some definite relation to the length 
of the period of growth." Therefore, as the period of 
growth is, so to say^ inherent in the species, longevity 
would have to be regarded as a very stable phenomenon. 
Just as any species has acquired a fixed and practically 
invariable size, so it would have acquired a definite longe- 
vity. Buffon, therefore, thought that the duration of life 
did not depend on habits or mode of life, or on the nature 
of food, that, in fact, nothing could change its rigid laws, 
except an excess of nourishment. 

Taking as his standard the total period of development 
of the body, Buffon came to the conclusion that the dura- 
tion of life is six or seven times that of the period of 
growth. Man, for instance, he said, who takes 14 years 
to grow, can live 6 or 7 times that period, that is to say, 
90 or roo years. The horse, which reaches its full size 
in 4 years, can live 6 or 7 times that length of time, that 
is to say from 25 to 30 years. The stag takes 5 or 6 
years to grow, and reckoned in the same way, its longevity 
should be 35 to 40 years. 

Flourens 2 although supporting his principle, thought 
that Buffon had been inexact in calculating the period 
of growth. In his opinion a better result can be obtained 
by taking the limit of growth as that age at which the 
epiphyses of the long bones unite with the bones them- 

1 Histoire natitrelle gtntrale et particultire, vol. ii. Paris, 1749. 

2 De la longtvitl humaine et de la quantitt de vie sur le globe ', Paris, 


selves. Using such a mode of computation, Flourens laid 
down that an animal lived 5 times the length of its period 
of growth. Man, for instance, takes 20 years to grow, and 
he can live for 5 times that space, that is to say, 100 years ; 
the camel takes 8 to grow, and lives 5 times as long, 
i.e., 40 years; the horse, 5 to grow, and lives 25 years. 

However, even if we consider only the mammalia, it is 
impossible to accept Flourens' law, without considerable 
reserve. Weismann l has referred to the case of the horse, 
which is completely adult at 4, but lives not merely 5 
times that period, but 10 or even 12 times. Mice grow 
extremely quickly, so that they are able to reproduce at 
the age of 4 months. Even if we take 6 months as their 
period of growth, their longevity of 5 years is twice as 
long as it would be according to the rule of Flourens. 
Amongst domesticated animals, the sheep is slow in reach- 
ing maturity ; it does not acquire its adult set of teeth until 
it is 5 years old, and cannot be regarded as adult until 
then. None the less, at the age of 8 or 10 years, it loses 
its teeth and begins to grow old, whilst by 14 it is quite 
senile. 2 The longevity of the sheep, therefore, is not quite 
three times its period of growth. 

If we turn to other vertebrates, the variations in the 
relation of growth and the duration of life are still greater. 
Parrots, for instance, the longevity of which is extremely 
great, grow very quickly. At the age of 2 years, they 
have acquired the adult plumage and are able to repro- 
duce, whilst the smaller species are in the same condition 
at the age of one. Incubation, moreover, is very short, 
not more than 25 days, and in some species not three 
weeks. None the less, parrots are birds which enjoy a 

1 Ueber die Dauer des Lebens, Jena, 1882, p. 4. 

2 Brehm, La vie des animaux, Mammtjeres, vol. ii. p. 623. 


quite remarkable longevity. The incubation period of 
domestic geese is 30 days, and their period of growth is 
also short. However, they may reach a great age, cases 
of 80 years and of 100 years being on record. In contrast 
with these, ostriches, the incubation period of which is 
42 to 49 days, and which take 3 years to become adult, 
have a relatively short life. 

H. Milne-Edwards 1 many years ago contended that 
there was no importance in the supposed law of relation 
between gestation and longevity. He sums up his criticism 
as follows : " Although the period of uterine life is longer 
in the horse, that animal does not live so long as a human 
being; and some birds, the incubation of which only lasts 
a few weeks, can live more than a century." 

Bunge 2 has recently taken up the study of the relations 
between the duration of growth and longevity, and has 
suggested a new means of investigation. He has observed 
that the period in which the new-born mammal doubles 
its weight is a good index of the rapidity of its growth. 
He has shown that whilst a human child requires 180 
days to reach double its weight at birth, the horse, the 
longevity of which is very much less, doubles its weight 
in 60 days; a calf takes only 47 days for this; a kid 15 
days; a pig 14 days; a cat 9^; and a dog only 9 days. 
Although these facts are very interesting, the exceptions 
are too great to make it possible to base a law of longevity 
upon them. The period of weight-doubling in the horse 
is nearly 7 times longer than that in the dog, and yet the 
longevity of the horse is not more than 3 times that of 
the dog. The goat, which takes much longer than the 
dog to double its weight, has a shorter total life. 

1 Leqons sur la physiologic et P anatomic comparee, vol. ix. 1870, 
p. 446. 

2 Archivf. die gesammte Physiologic^ Bonn, 1903, vol. xcv. p. 606. 


I observed myself that new-born mice quadruple their 
weight in the first 24 hours. The doubling of weight 
in their case requires a time 36 times less long than that 
of the cat, and yet the cat lives only 5 times as long as 
the mouse. 

It is fair to say, however, that Bunge himself does not 
draw a definite conclusion from these figures and has 
published them only to stimulate interest in the subject. 
He is against the view of Flourens, and points out that 
although the multiple 5 is valid for man, it is not so in 
the case of the horse which finishes its growth in 4 years 
and yet reaches the age of 40 much less often than human 
beings attain that of 100 years. 

Although it is impossible to admit the existence of 
exact relations between size and the period of growth on 
the one side, and longevity on the other, in the mode 
which Buffon and Flourens have followed, it is none the 
less true that there is something intrinsic in each kind 
of animal which sets a definite limit to the length of years 
it can attain. The purely physiological conditions which 
determine this limit leave room for a considerable amount 
of variation in longevity. Duration of life therefore, is 
a character which can be influenced by the environment. 
Weismann in his well-known essay on the duration of 
life, has laid stress on this side of the problem. Longevity, 
according to him, although in the last resort depending 
on the physiological properties of the cells of which the 
organism is composed, can be adapted to the conditions 
of existence and influenced by natural selection, like other 
characters useful for the existence of the species. 

If a species is to remain in existence, its members must 
be able to reproduce and the progeny must be able to 
reach adult life so that they in their turn may reproduce. 
Now, it happens that there are some animals the fecundity 


of which is extremely limited. Most birds which are 
adapted to aerial life, and the weight of which is therefore 
to be kept down, lay very few eggs. This happens in 
the case of birds of prey, such as eagles and vultures. 
These birds nest only once a year, and generally rear two 
or frequently only a single nestling. In such circum- 
stances the duration of life becomes a factor in the preserva- 
tion of the species, more important since eggs and chicks 
are subject to many dangers. Eggs are devoured by many 
kinds of animals, whilst unseasonable cold may kill the 
chicks. If the members of such a species were incapable of 
living long, the unfavourable conditions of life would soon 
Jead to extinction. Those animals which reproduce rapidly 
generally have a relatively brief duration of life. Mice, rats, 
rabbits, and many other rodents seldom live more than 5 or 
10 years, but reproduce with enormous rapidity. It is almost 
possible to imagine that there is some sort of intimate link, 
possibly physiological, between longevity and low fertility. 
It is a current opinion that reproduction wastes the maternal 
organism and that mothers of many children grow old 
prematurely and seldom reach an advanced age. This 
would seem to mean that fecundity was the cause of the 
short duration of life. However, we must guard ourselves 
against such a theory. Longevity, at least in the case of 
vertebrate animals, differs extremely little in the two sexes, 
although the cost of the new generation to the adult 
organism is very much greater in the case of the female 
than of the male parent. None the less, females frequently 
reach a great age, especially in the human race where 
women reach 100 years, or live beyond that time, much 
more often than men. 

Low fertility, however, cannot itself be regarded as a 
cause of longevity, as there are some very fertile animals 


which none the less attain great ages. There are parrots 
which lay two or three times a year, producing six to nine 
eggs in each clutch. The ducks (Anatidae) are distinguished 
for considerable longevity and very high fertility, each 
nest containing rarely less than six and sometimes as many 
as sixteen eggs. The common Sheldrake lays from twenty 
to thirty eggs. Tame ducks, in some parts of the tropics, 
lay an egg daily throughout the season. Wild ducks lay 
from seven to fourteen eggs in one nest. Ducks and geese, 
none the less, frequently attain considerable ages, ducks 
having been known to live for 29 years. Even the common 
fowl, which is a notoriously prolific bird, may reach an age 
of twenty to thirty years. 

It will be said, however, that these birds are exposed to 
many enemies during youth. Chickens, ducklings, and 
goslings are ready prey for hawks, foxes and small carni- 
vora. The longevity is possibly to be explained as an 
adaptation for the preservation of the species by compen- 
sating for the great destruction of the young. Weismann 
explains in this way the longevity of many aquatic birds 
and other creatures that are much preyed on. It must be 
noted, however, that the longevity cannot depend on the 
risks run by the young birds, but must have arisen in- 
dependently. If this had not occurred, creatures, the young 
of which are destroyed in great numbers, would have ceased 
to exist, as many species have disappeared in geological 
time. The longevity of prolific animals, the young of 
which are destroyed in numbers, must be due to some 
cause which is neither fertility nor the destruction of their 
offspring. This cause must be sought in the physiological 
processes of the organism and can be attributed neither to 
the length of the period of growth nor to the size attained 
by the adults. 


After having discussed various theories of the cause of 
the duration of life, M. Oustalet, 1 in a most interesting essay 
on the longevity of vertebrates, came to the conclusion that 
diet was the chief factor. He thinks that there is a 
" definite relation between diet and longevity. For the most 
part herbivorous animals live longer than carnivorous 
forms, probably because the former find their food with 
ease and regularity, whilst the latter alternate between 
semi-starvation and repletion." There are certainly many 
instances which give support to the view. Elephants and 
parrots, for instance, are vegetarian and reach very great 
ages. On the other hand, there exist long-living carni- 
vorous animals. Many observations have made it certain 
that owls and eagles reach great ages, and these birds live 
on animal food. Ravens, which live on carrion, are also 
notorious for the duration of their lives. There is no exact 
knowledge as to the ages reached by crocodiles, but 
although these live on flesh, it is certain that their longevity 
is great. 

We must seek elsewhere for the real factors that control 
duration of life. Before stating my conclusion, I will 
review what is known as to the duration of life of different 

1 La Nature, May 12, 1900, p. 378. 



Longevity in the lower animals Instances of long life in 
sea-anemones and other invertebrates Duration of life of 
insects Duration of life of " cold-blooded " vertebrates 
Duration of life of birds Duration of life of mammals 
Inequality of the duration of life in males and females 
Relations between longevity and fertility of the organism 

IT is wonderful to what an extent the duration of life varies 
amongst animals, the slightest examination of the facts 
showing that very many factors must be involved. 

As the higher animals are nearly always larger than 
invertebrates, if there be a definite relation between long- 
evity and size, one would expect to find that vertebrates 
live longer than invertebrates. However, this is not the 
case. Amongst animals of extremely simple organisation, 
there are some which reach a great age. A striking 
example of this is found in sea-anemones. These animals 
have a very simple structure, without a separate digestive 
canal, and with a badly developed, diffused nervous system, 
and yet have lived very long in captivity. More than forty 
years ago, I remember having seen in the possession of 
M. Lloyd, the Director of the Aquarium at Hamburg, an 
anemone that he had kept alive for several dozen years 'in 
a glass bowl. Another sea-anemone, belonging to the 
species Actinia mesembryanthemum, is known to have 
lived 66 years. It was captured in 1828 by Dalyell, a 


Scottish zoologist, and was then quite adult, and probably 
about 7 years old. It survived its owner for 36 years, and 
died in Edinburgh in 1887, the cause of death being un- 
known. Although they are thus capable of living so long, 
the rate of growth of members of this species is rapid, and 
their fertility is very high. According to Dalyell, these 
anemones reach the adult condition in 15 months. The 
specimen in his possession, in the 20 years from 1828 to 
1848 produced 334 larvae, then after a period of sterility it 
gave birth, in one night (1857) to 2 3 young anemones. 
This extraordinary prolificness decreased with age, but even 
when it was 58 years old it used to produce from 5 to 20 at 
a time. In the seven years from 1872 onwards, it gave birth 
to 150 young anemones. 1 This animal, which certainly 
was not more than the fortieth or the fiftieth of the weight 
of an adult rabbit, lived six or seven times as long. 

Ashworth and Nelson Annandale have published their 
observations on another sea-anemone, of the species Sagartia 
troglodytes, which was 50 years old. It differed from 
younger examples only in being less prolific. 

There are other polyps, such as Flabellum, which do not 
live more than 24 years, although we have no knowledge as 
to the cause of the different duration of life. 

The variation in the length of the life of molluscs and 
insects is extremely great. Some species of gasteropods 
(Vitrina, Succinea) live only a very few years, whilst 
others (Natica heros) can reach thirty years. Some of the 
marine bivalves, as for instance, Tridacna gigas, can live 
to sixty or a hundred years. 2 

Insects are animals as variable in their duration of life as 
they are in other respects. Some live only a few weeks; 

1 Ashworth and Annandale, Proceedings of the R. Society of Edinburgh, 
vol. xxv. part iv. 1904. 

' l Ilrcnn's Klassen u. Ordnungen des Thierreichs, vol. iii. p. 466. 


some of the plant-lice, for instance, die in a month. In 
the same order of Insects, however, (Hemiptera) there are 
species of cicada which live thirteen to seventeen years, that 
is to say, much longer than such little Rodents as rats, 
mice, and guinea-pigs. The larva of an American species 
spends seventeen years buried in the ground in orchards, 
where it feeds on the roots of apple trees, and the species is 
known as Cicada septemdecim, because of this duration of 
life. In the adult stage the insect lives little more than a 
month, just time enough to lay the eggs, and bring into 
the world the new generation, which in its turn will not 
appear above ground until after another period of seven- 
teen years. 

Between these extremes of long and short life, there is 
to be found amongst insects almost every gradation of 
longevity. Science, in its present state, has failed to find 
any law governing these facts. Rules which hold good up 
to a certain point in the case of the higher animals break 
down in their application to insects. The large grass- 
hoppers and locusts, for instance, live a much shorter time 
than many minute beetles. Queen bees, the fertility of 
which is very great, live two or three years and may reach 
a fifth year, whilst worker bees, which are infertile, die in 
the first year of their existence. Female ants, although 
these are small and extremely prolific, reach the age of 
seven years. 1 

We know so little about the physiological processes of 
insects, that we cannot as yet make even a guess at the 
cause of this great variation in their longevity. It is more 
probable that we shall find some explanation in the case of 
vertebrates concerning which we know much more. 

Analysis of the facts shows that whilst in the evolution 

1 Weismann, The Duration of Life, in "Essays on Heredity (English 
translation), Oxford, 1889. 



from fish to mammal there has been a great increase in 
complexity of organisation, there has at the same time been 
a reduction in the duration of life. As a general rule, it 
may be laid down that the lower vertebrates live longer 
than mammals. 

The facts about the longevity of fish are not very numer- 
ous, but it seems clear that these animals reach a great 
age. The ancient Romans, who used to keep eels in 
aquaria, have noted that these fish would live for more than 
sixty years. There is reason to believe that salmon can 
live for a century, whilst pike live much longer. There is, 
for instance, the much quoted instance of the pike stated 
by Gessner to have been captured in 1230 and to have lived 
for 267 years afterwards. Carps are regarded as equally 
long lived, Buffon setting down their period of life as 150 
years. There is a popular idea that the carp in the lakes 
at Fontainebleau and Chantilly are several centuries old, 
but E. Blanchard throws doubt on the accuracy of this esti- 
mate, inasmuch as during revolutionary times most of the 
carp were eaten when the palaces were overrun by the popu- 
lace. There is no doubt, however, that the life of carp 
may be very long indeed. Not very much is known about 
the duration of life in batrachians, but it is certain at least 
that some small frogs may live twelve or sixteen years, and 
toads as many as thirty-six years. 

More is known about the life of reptiles. Crocodiles and 
caymans, which are large and which grow very slowly, 
attain great ages. In the Paris Museum of Natural History 
there are crocodiles which have been kept for more than 
forty years without showing signs of senescence. Turtles, 
although they are smaller than crocodiles, live still longer. 
A tortoise has lived for eighty years in the garden of the 
Governor of Cape Town, and is believed to have reached 


the age of two hundred years. Another tortoise, a native 
of the Galapagos Islands, is known to be 175 years old, 
whilst a specimen in the London Zoological Gardens is 150 
years old. A land tortoise (Testudo marginata) has been 
kept in Norfolk, England, for a century. I am informed 
that in the Archbishop's palace at Canterbury, there is to 
be seen the carapace of a tortoise which was brought to the 
Palace in 1623 and which lived there for 107 years. 1 Another 
tortoise, brought to Fulham by Archbishop Laud, lived in 
the Palace for 128 years. I have already referred to a 
specimen of Testudo mauritanica, the history of which is 
known for 86 years, but which is probably much older. 

Very little is known as to the longevity of lizards and 
serpents, but it may be inferred from what I have said about 
other reptiles that reptiles as a class are able to reach great 

It is an easy inference that the great duration of life in 
cold-blooded animals is associated with the slowness of 
the physiological processes in these creatures. The circu- 
lation, for instance, is so slow, that the heart of a tortoise 
beats only 20 to 25 times in a minute. Weismann has 
suggested that one of the factors influencing the duration 
of life is the rapidity or slowness of the vital activities, the 
times taken by the processes of absorption and nutrition. 

On the other hand, the blood is hot and the vital activities 
are rapid in birds, and yet birds may attain great ages. 
Although in the last chapter I gave a number of examples, 
the subject is so important that I propose to go further into 
details. The possibility of this is due to an admirable set 
of details brought together by Mr. J. H. Gurney. 2 In his 

1 Oustalet, "La Longtvitt chez les Animaux ver&fMs," La Nature, 
May 12, 1900, p. 378. 

2 " On the Comparative Ages to which Birds tive," The Ibis, Jan., 
1899, vol. v. p. 19. 

E 2 


list, in which are included more than fifty species of birds, 
the lowest figures are from eight and a half to nine years 
(Podargus cuvieri, Chelidon urbica), and a duration of life 
so short is an exception, a period of from fifteen to twenty 
years being more common. Canaries have lived in cap- 
tivity from 17 to 20 years, and goldfinches up to 23 years. 
Field larks have lived for 24 years, the Lesser Black-backed 
Gull 31 years and the Herring Gull 44 years. Birds of 
medium size may live for several dozens of years, whether 
they live on animal or on vegetable food, whether they are 
prolific or lay very few eggs. I will quote only a few 
instances. Of forty parrots the minimum and maximum 
ages were respectively 15 and 81 years, and the average 43 
years. Without accepting the truth of the story mentioned 
by Humboldt according to which certain parrots survived 
an extinct race of Indians, at least we may be certain that 
great ages have sometimes been reached by these birds. 
Levaillant mentions a parrot (Psittacus erithaceus) which 
lost its memory at the age of 60 years, its sight at 90 
years, and which died aged 93 years. Another individual, 
probably of the same species, is reported by J. Jennings 
to have reached the age of 77. Jones, Layard, and Butler 
are the authorities for instances of Sulphur-crested Cocka- 
toos having reached respectively 30, 72 and 81 years. M. 
Abrahams states that an Amazon (Chrysotis amasonica) 
lived 1 02 years. I myself have observed two cases of great 
longevity in the same species of parrot. One of these birds 
died at the age of 82 years, apparently simply from old 
age, whilst the other, which was in my possession for 
several years before it died at the age of 70 to 75 years, was 
vigorous, showing no signs of senility, but died of pneu- 

Mr. Gurney found that parrots were not the only birds 


capable of reaching a great age. One raven reached 69 
years and another 50, an Eagle-owl (Bubo maximus) 68 
years, another 53, a condor 52, an imperial eagle 56, a com- 
mon heron 60, a wild goose 80, and a common swan 70 
years. None of these examples approaches the legendary 
three centuries attributed to the swan, but it is evident that 
many different kinds of birds may attain great age. I can 
add some cases to those of Mr. Gurney. In the Royal Park 
at Schonbrunn, near Vienna, a white-headed vulture (Neo- 
phron percnopterus) died aged 118 years, a golden eagle 
(Aquila chrysaetus) aged 104, and another aged 80 (accord- 
ing to Oustalet). Mr. Pycraft (Country Life, June 25th, 
1904) reported that a female eagle, captured in Norway in 
1829, had been brought to England and had lived for 75 
years. In the last thirty years of its life, it had produced 
ninety eggs. The same writer mentions the case of a falcon 
having lived to 162 years. 

The collection of facts that I have passed in review make 
it manifest that birds may have a great duration of life, 
but that reptiles surpass them in this respect. Birds cer- 
tainly do not reach the very great ages of crocodiles and 

Longevity, therefore, is reduced as we ascend in the 
scale of vertebrate life. We find a still greater reduction 
when we turn from birds to mammals. Some mammals, 
it is true, may live as long as birds. Elephants are a 
good instance. It used to be thought that these giant 
mammals could live three or four centuries, but I can find 
no confirmation of the legend, which seems as mythical 
as that relating to the life of swans. There are no exact 
data as to the ages reached by wild elephants, but it has 
been stated that in captivity an elephant rarely but occa- 
sionally has completed its century. In zoological gardens 


and in good menageries, where elephants are well cared 
for, they seldom live more than 20 to 25 years. Chevrette, 
an African elephant presented to the Jardin des Plantes 
by Mehemet AH, in 1825, lived for only 30 years. In the 
official list of the Indian Government, which gives the 
fteaths of elephants, it appears that of 138 examples, only 
one lived more than 20 years after it had been purchased 
(Brehm's Mammals). 

Flourens, using his own formula, assigned the age of 
150 years to elephants as their epiphyses do not fuse with 
the long bones until the age of 30. So far, I know 7 of no 
fact to support the conclusion, although it seems fairly well 
established that occasionally an elephant may reach a 
century. It is stated that one elephant was in service 
throughout the whole period of more than 140 years in 
which Ceylon was occupied by the Dutch. This elephant 
was found in the stables in 1656. Natives with special 
knowledge of elephants set down their duration of life 
as from 80 to 150 years, but say that they begin to grow 
old at from 50 to 60 years of age. My general conclusion 
from the facts is that the life of these very large mammals 
is about the same as that of man who is very much 

Centenarians, extremely rare amongst elephants, do not 
appear to exist in any other kind of mammals except man. 
The rhinoceros, another large mammal which is a native 
of the same countries as the elephant, does not reach a 
great age. According to Oustalet an Indian rhinoceros 
died in the menagerie of the Paris Museum at about the 
age of 25 years, and showed all the signs of senility. 
Another Indian rhinoceros lived for 37 years in the London 
Zoological Gardens. Grindon has stated his opinion that 
the rhinoceros may live for 70 or 80 years, but this seems 


rather an inference from the slowness of growth than a 
statement of observed fact. 

Horses and cattle are large animals, hut do not enjoy 
very long lives. The usual duration of life in horses is 
from 15 to 30 years. They begin to grow old about 10 
years, and in very rare cases may reach 40 or more. A 
Welsh pony is said to have reached the age of sixty, but 
such a case is excessively rare. Two other extreme cases 
are that of a horse belonging to the Bishop of Metz which 
died at the age of 50 years, and the charger of Field- 
Marshal Lacy which died at 46. 

The duration of life of cattle is still shorter. Domestic 
cattle show the first sign of age, a yellow discoloration 
of the teeth, when five years old. In the sixteenth to 
eighteenth year the teeth fall out, or break, and the cow 
ceases to give milk, whilst the bull has lost reproductive 
power. According to Brehm, cattle live for 25 to 30 years 
or more. Although the duration of life is short, cattle 
are not prolific. The gestation period of a cow approaches 
that of the human race (242-287 days), and there is only 
one birth a year. The total period of reproductivity lasts 
only a few years. 

The sheep, another domesticated Ruminant, has a life 
even shorter. According to Grindon, sheep do not live 
longer than 12 years as a rule, but may reach 14 years, 
which in their case would be extreme age, as they generally 
lose their teeth at from 8 to 10 years. 

Some Ruminants, such as camels and deer, apparently 
live longer than sheep or cattle, but I do not know exact 
facts about them. 

The short life of domesticated carnivorous animals is 
well known. Dogs seldom live more than 16 or 18 years, 
and even before that,- at an age of from 10 to 12, they 


usually show plain signs of senility. Jonatt has mentioned 
as an extreme rarity a dog of 22 years of age, and Sir E. 
Ray Lankester (Comparative Longevity, p. 60) cites 
another instance, in this case the age being 34 years. The 
oldest dog that I have been able to procure died at the 
age of 22. 

It is generally believed that cats do not live so long as 
dogs. The average age which they may attain is usually 
thought to be 10 or 12 years, but certainly a cat of that 
age has not the decrepid appearance of an old dog. Thanks 
to the kindness of M. Barrier, the Director of the Ecole 
d'Alfort, I have had in my possession a cat 23 years old. 
It appeared to be quite vigorous, and died from cancer 
in the liver. 

Most rodents, particularly the domesticated kinds, are 
extremely prolific and very short lived. It is extremely 
rare for a rabbit to reach the age of 10 years, whilst 7 
years is the utmost limit for a guinea-pig. Mice, so far 
as I can ascertain, do not live more than 5 or 6 years. 

It is plain from the facts that I have brought together, 
that mammals, whether they are large or small, as a rule, 
have shorter lives than birds. It is probable, therefore, 
that there is something in the structure of mammals which 
has brought about a shortening in the duration of their 

Whilst most of the lower vertebrates, and all birds, 
reproduce by laying eggs, the vast majority of mammals 
are viviparous. As the tax on the parent organism is 
greater when the young are produced alive than when 
eggs are laid, it might be thought that in this difference 
lay the cause of the shorter life of mammals. It is well 
known that an animal may be made feeble by too great 
fecundity, and it is conceivable that the kind of parasitic 


life of the embryos within the body of the mother may 
weaken her system. 

There are many facts, however, which make it impos- 
sible to accept such a view. The longevity of mammals 
is nearly equal in the two sexes, although the tax on the 
organism caused by reproduction is much greater in the 
case of females than in males. Longevity, however, 
cannot be regarded as a character stable in each species 
and necessarily identical in the two sexes. The animal 
kingdom presents many cases of disparity in this respect, 
the difference in longevity in the tw ; o sexes being specially 
striking in species of insects. Generally, the females live 
longer than the males, as, for instance, amongst the Strep- 
si ptera, where the females have 64 times the duration of 
life of the males. On the other hand, amongst butterflies, 
there are cases (e.g., Aglia tau) where the males live longer 
than the females. In the human race, there is a difference 
in the longevity of the sexes, the females having the 

As in most cases of disparity in the duration of life the 
female lives longer than the male, it is plain that the differ- 
ence cannot be assigned to the drain on the organism 
caused by reproduction, which, of course, is much greater 
in females. 

Moreover, a closer scrutiny of the facts shows that 
although mammals do not live so long as birds, the repro- 
ductive drain is greater in the case of birds. 

It is well known that the productivity of an animal is 
not necessarily identical with its fecundity. Fish or frogs 
which lay thousands of eggs at a time (a pike, for example, 
produces 130,000) are obviously more prolific than, for 
instance, a sparrow which lays only 18 eggs in a year, 
or than a rabbit, which in the same time gives birth to 


from 25 to 50. However, to produce this much smaller 
quantity of eggs or of young, the sparrow and the rabbit 
(I have chosen the most prolific bird and mammal) expend 
a much larger quantity of material than the frog or the 
fish. The sparrow and the rabbit employ in producing 
their progeny a bulk of material greater than the weight 
of their body, whilst the enormous quantity of eggs laid 
by the frog does not weigh more than one-seventh part of 
the body of the frog. It may be laid down, as a general 
rule, that although fecundity, that is to say the number 
of eggs or of young which are produced, diminishes as 
the organism becomes more complex, the productivity on 
the other hand increases, expressed in percentage of weight. 
The productivity, which is not more than 18 per cent, in 
batrachia, reaches 50 per cent, in reptiles, 74 per cent, 
in mammals, and 82 per cent, in birds. 

It is plain that if reproduction shortens the life of 
mammals by weakening the organism, it must be the 
productivity, not the fecundity, which is the important 
factor. I have just shown that productivity is greater in 
birds than in mammals, and in consequence it cannot be 
on account of any greater burden of reproduction that 
mammals have a shorter life than birds. The shortness 
of mammalian life, again, cannot be attributed to the fact 
that mammals give birth to young, whilst the long-lived 
reptiles and birds produce eggs, because the longevity of 
the males, which produce neither young nor eggs, is none 
the less practically equal to that of the females of the same 
species. The reason of the short life of mammals must 
be sought for elsewhere. 



Relations between longevity and the structure of the digestive 
system The Caeca in birds The large intestine of mammals 
Function of the large intestine The intestinal microbes 
and their agency in producing auto-intoxication and auto- 
infection in the organism Passage of microbes through the 
intestinal wall 

WE have seen that the duration of life in mammals is 
relatively shorter than that in birds, and in the so-called 
" cold-blooded " vertebrates. No indication as to the cause 
of this difference can be found in the structure of the organs 
of circulation, respiration, or urinary secretion, or in the 
nervous or sexual apparatus. The key to the problem is 
to be found in the organs of digestion. 

In reviewing the anatomical structure of the digestive 
apparatus in the vertebrate series, one soon comes to the 
striking fact that mammals are the only group in which the 
large intestine is much developed. In fish, the large intes- 
tine is the least important part of the digestive tube, being 
little wider in calibre than the small intestine. Amongst 
batrachia, where it is a relatively wide sack, it has begun 
to assume some importance. In several reptiles it is still 
larger, and may be provided with a lateral out-growth, 
which is to be regarded as a caecum. In birtis, the large 
intestine still remains relatively badly developed; it is 


short and straight. In most birds, at the point where the 
large intestine passes into the small intestine, there is a 
pair of caeca, more or less developed. These caeca are 
absent in climbing birds, such as the wood-pecker, the 
oriole, and many others. They are reduced to a pair of 
tiny out-growths in the eagles, sparrow-hawks, and other 
diurnal birds of prey, and in pigeons, and perching birds. 
These organs are larger in the nocturnal birds of prey, in 
gallinaceous birds, and in ducks, etc. 1 

In the large running birds, such as ostriches, rheas, and 
tinamous, the caeca are relatively largest. Thus, for 
instance, in a rhea (Rhea americana) which I dissected, the 
caeca were nearly two-thirds as long as the small intestine. 
The latter was 1*65 m. in length, whereas one of the caeca 
was roi m., and the other 0*95 m. The weight of the 
two caeca with their contents was more than 10 per cent, 
of the total weight of the bird. 

Notwithstanding the exceptions, which are relatively 
rare, the large intestine is badly developed in the case 
of birds. On the other hand, it reaches its largest size 
amongst mammals. In these animals, " only the posterior 
portion of the latter, or rectum, which passes into the 
pelvic cavity, corresponds to the large intestine of 
lower Vertebrates; the remaining, and far larger part, 
must be looked upon as a neomorph, and is called the 
colon." 2 

Gegenbaur, 3 another well-known authority on compara- 

1 J. Maumus, " Les caecums des oiseaux," Annales des sciences naturel- 
les, 902. See also P. Chalmers Mitchell, " On the Intestinal Tract of 
Birds," Trans. Linnaan Soc. of London, vol. viii. part 7, 1901. 

2 Weidersheim, Elements of the Comparative Anatomy of Vertebrates, 
translated by \V. Newton Parker, p. 236, 1886. 

3 Elements of Comparative Anatomy, English translation by F. Jeffrey 
Bell, B.A., London, 1878, p. 562. 


tive anatomy, writes as follcv.s on this subject: "The 
hind-gut is longest in the Maimv.- tr a, where it forms the 
large intestine, and is distinguish 3 as such, from the 
mid-gut, or small intestine. Owing ro its greater length, 
it is arranged in coils, so that the terminal portion only 
has the straight course taken by the hind-gut of other 

The two series of facts are not to be disputed. On the 
one hand mammals are shorter lived than birds and lower 
vertebrates, on the other hand the large intestine is much 
longer in them than in any other vertebrates. Is there 
here any link of causality, binding the two Characters, or 
is it a mere coincidence? 

To answer the question we must turn to the function of 
the large intestine in vertebrates. In the lower members 
of the group (fish, batrachia, reptiles, birds, etc.), the 
large intestine is not more than a mere reservoir for the 
waste matter in the food. It takes no share in digestion, 
as that is the function of the stomach and the small intes- 
tine. Only the caecum can be thought to have some 
digestive property. In reptiles, the lowest vertebrates in 
which the caecum is present, it is so little differentiated 
from the large intestine itself, that it is difficult to assign 
to it any specialised function. In very many birds, how- 
ever, the caeca are well separated from the main diges- 
tive tube. The food material passes into them in con- 
siderable quantities, and is retained there sufficiently long 
for some digestive process to take place. M. Maumus 
has found, in the caeca of birds, secretions which can dis- 
solve albumen and invert sugar cane, but he has been 
unable to make out that the caecal juice has any action 
upon fatty matter. Such digestive power, however, is 
slight, and when M. Maumus removed the caeca in fowls 


and ducks, no evil consequences followed. As in many 
birds the caeca are rudimentary and in others absent, it 
may be inferred that these organs are useless, and are 
in process of degeneration in the class. The caeca can 
be regarded as playing an important part in the organism 
only in the case of large running birds, where they are 
very highly developed, but we have not precise informa- 
tion as to their digestive function. 

The variations in the structure in the large intestine 
are greater in mammals than in birds. In some mammals, 
the large intestine is a simple prolongation of the small 
intestine, similar in calibre and in structure. In these con- 
ditions it may fulfil a definite digestive function. Th. 
Eimer 1 has determined that in insectivorous bats the 
large intestine digests insects like the small intestine. 
Such cases, however, are rare. In most mammals the 
large intestine is sharply separated from the small intes- 
tine by a valve, and opens directly into the caecum which 
may be very large. In the horse, the caecum is an enormous 
bag, cylindrical and tapering, generally well filled, and 
holding on an average 35 litres. It is equally large in 
many other herbivorous animals, such as the tapir, the 
elephant, and most rodents. In such cases, the food 
remains for a considerable time in the organ and without 
doubt undergoes some digestive changes. In many other 
mammals, particularly carnivorous forms, the caecum may 
be quite absent, whilst in some, as for instance, the cat 
and dog, it is very small ; in the latter cases its digestive 
function must be non-existent or insignificant. 2 

As for the large intestine itself, apart from the special 

1 Virchov/s Archiv, 1869, vol. xlviii. p. 151. 

* P. Chalmers Mitchell, " On the Intestinal Tract of Mammals," Trans. 
Zool. Soc. of London, vol. xvii. part 5, 1905. 


cases, such as bats, it cannot fulfil any notable digestive 
function. Th. Eimer was unable to find a proof of any 
such action in rats and mice, and the very many investiga- 
tions that have been made in the case of man seem to 
have established the absence of digestive power in the 

Dr. Stragesco, 1 in a recent investigation carried out 
under the direction of the famous Russian physiologist 
Pawloff, established that, in normal conditions, digestion 
and assimilation of food are confined almost exclusively to 
the small intestine in mammals, and that the large intes- 
tine plays only the smallest part. It is only in certain 
diseases of the digestive tract, in which, on account of 
increased peristaltic action, the contents of the intestine 
with the digestive juices are passed quickly from the small 
intestine to the large intestine, that some digestive work is 
done in the latter organ. 

The large intestine (excluding the caecum), then, cannot 
be regarded as an organ of digestion, although ab- 
sorption of the liquids which have been formed in the 
small intestine, may take place within its walls. It is 
known that in the large intestine the contents of the gut 
give up their water and assume the solid form of faecal 
matter. However, whilst the mucous membrane of the 
large intestine rapidly absorbs water, it has not a similar 
action on other substances. 

The question of the extent to which the large intestine 
can absorb has been closely investigated, because of its 
practical importance. It sometimes happens that invalids 
cannot take food by the mouth, so that their life would be 
in danger if it were not possible to supply them with food 

1 Tra-vaux de la Socittt des mddecins russes a Saint- Pttersbourg. 
September-October, 1905, p. 18 (in Russian). 


otherwise. Attempts have been made to inject nutritive 
substances through the skin, or, and this is a more usual 
procedure, by the rectum. By such means the organism 
can be kept alive for a certain time, but the absorbing 
power of the large intestine is extremely small. Accord- 
ing to Czerny and Lautschenberger l the entire colon of 
the human being can absorb no more than 6 grammes of 
albumen in 24 hours, an amount which, from the point of 
view of nutrition, is very small. It was thought that the 
large intestine might more rapidly absorb albuminous 
material which had been previously digested and trans- 
formed to peptones, but the experiments of Ewald 2 showed 
that even in that case the absorption was very small. 
According to more recent experiments of Heile, 3 carried 
out upon dogs which had caecal fistulas, and in the case 
of a man who had an artificial aperture in the colon, the 
large intestine does not absorb undigested white of egg, 
and absorbs water, cane sugar, and glucose only very im- 
perfectly. The only substances which are rapidly ab- 
sorbed through the wall of the colon are the alkaline fluids 
from faecal matter. It is possible, however, to nourish 
invalids by rectal injections of certain nutritious substances, 
the most important of which is milk. 4 

The large intestine, which has really very slight diges- 
tive properties and cannot absorb any considerable bulk 
of nutriment, is an organ which secretes mucus. The 
latter serves to moisten the solid faecal material, so aiding 
in its expulsion. 

We must conclude, therefore, that the large intestine, 
the organ so highly developed in mammals, is an apparatus 

1 Virchow's Archiv, 1874, vol. lix, p. 161. 

2 Zeitsckrift f. klinische. Median, 1887, vol. xii. 

3 Mittheilungen a. d. Grenzgebieten d. Medicin u. Chirurgie, 1905. 
vol. xiv. 

4 Aldor, Centralblatt f. innere Medicin, 1898, p. 161. 


the general function of which is the preparation and elimi- 
nation of the waste products of digestion. Why should 
such an organ be so much more developed in mammals 
than in the other vertebrates ? 

In answer to the question, I have formed the theory that 
the large intestine has been increased in mammals to make 
it possible for these animals to run long distances without 
having to stand still for defalcation. The organ, then, 
would simply have the function of a reservoir of waste 

Batrachia and reptiles lead a very idle life, and can move 
slowly, sometimes because they are protected by poison 
(toads, salamanders, serpents), sometimes because they 
have a very hard shell (turtles), sometimes because they 
are extremely powerful (crocodiles). Mammals, on the 
other hand, have to move very actively to catch their prey, 
or to escape from their enemies. Such activity has 
become possible because of the high development of the 
limbs, and because the capacity of the large intestine makes 
possible the accumulation of waste matter for a consider- 
able time. 

In order to void the contents of the intestines, mammals 
have to stand still and assume some particular position. 
Each act of this kind is a definite risk in the struggle for 
existence. A carnivorous mammal which, in the process 
of hunting its prey, had to stop from time to time, would 
be inferior to one which could pursue its course without 
pausing. So, also, a herbivorous mammal, escaping from 
an enemy by flight, would have the better chance of sur- 
viving the less it was necessary for it to stand still. 

According to such a view, the extreme development of 
the large intestine would supply a real want in the struggle 
for existence. M. Yves Delage, 1 the well-known biologist, 

1 Lanntebiologique, 7th year, 1902. Paris, 1903, p. 590. 



is unable to accept this hypothesis. He thinks that the 
rectal enlargement would fulfil the purpose, and adds that 
everyone has seen herbivorous animals pass their excre- 
tions whilst running. The rectum of mammals, however, 
cannot serve as a reservoir for waste matter, because as soon 
as such matter reaches the rectum it excites the need of 
excretion. The waste matter accumulates in the large in- 
testine, from which it passes into the rectum at intervals. 
When it has reached that region, a sensation is caused 
which leads to defalcation. 

M. Delage is not quite definite when he speaks of 
mammals voiding their excretions whilst they are in 
motion. A horse, harnessed to a vehicle, may defaecate 
whilst it is walking or even running slowly. But these 
animals cannot defaecate when in rapid motion, and com- 
petent observers state that horses never do so whilst racing. 
In zoological gardens, where animals have room to run 
about, they stand still before emptying the rectum. M. 
Ch. Debreuil, who keeps antelopes in a very large park 
at Melun, has noticed that the excreta are always to be 
found in masses and not scattered about as if they had been 
discharged by animals in motion. Antelopes, which are 
animals that run and leap extremely actively, have to come 
to a standstill before discharging their small pellets of 
deer-like excreta. 

In the struggle for existence, when a mammal is pursuing 
its prey or escaping its enemy, there is no question of the 
leisurely movement of a horse harnessed to an omnibus or 
cab, but the greatest possible activity is necessary. In 
such circumstances the possession of an organ within which 
the excreta could accumulate would be of real importance. 
My theory of the origin of the mammalian large intestine 
is intrinsically probable. 

Although the capacity of the large intestine may 


preserve a mammal in emergencies, it is attended with 
disadvantages that may shorten the actual duration of life. 

The accumulation of waste matter, retained in the large 
intestine for considerable periods, becomes a nidus for 
microbes which produce fermentations and putrefaction 
harmful to the organism. Although our knowledge of 
the subject is far from complete, it is certain that the in- 
testinal flora contains some microbes which damage health, 
either by multiplying in the organism, or by poisoning it 
with their secretions. Most of our knowledge on this 
matter has come from the study of human patients. 

Persons have been known who do not defalcate except 
at intervals of several days, and who, none the less, do not 
seem to suffer in health. But the opposite result is more 
common. The retention of faecal matter for several days 
very often brings harmful consequences. Organisms 
which are in a feeble state from some other cause are speci- 
ally susceptible to damage of the kind referred to. Infants 
are frequently seriously ill as the result of constipati9n. 
Dr. du Pasquier 1 describes such cases in the following 
words : " The infant is leaden in hue, 'with sunken eyes, 
dilated pupils, and pinched nostrils. The temperature may 
reach nearly 104 Fahr. ; the pulse is rapid, feeble, and often 
irregular. Restlessness, insomnia, sometimes convulsions, 
stiffness of the neck and strabism show that the nervous 
system is being poisoned by toxins, and even collapse may 
be reached. The foul and dry tongue, the vomiting and 
fetid discharges show the disturbance of the digestive tract. 
Very often an eruption appears, as described by Hutinel, 
chiefly on the back and buttocks, the front of the thighs and " 
fore-arms." The illness may lead to death but is generally 
cured by simple purging. 

1 Gazette des Hopitaux, 1904, p. 715. 

F 2 


Women in pregnancy and childbirth frequently suffer 
much as the result of retention of faecal matter, and 
physicians are familiar with the symptoms, which have 
been described as follows by M. Bouchet 1 : "After 
normal parturition, in the course of which the usual anti- 
septic precautions have been fully pursued, and where 
delivery has been complete and natural, occasionally the 
patient is seized with chill and headache. The breath is 
fetid and the tongue foul. The temperature, taken in the 
axilla, is nearly 101 Fahr. The abdomen is inflated and 
painful in the umbilical region. Palpation in the iliac 
fossae reveals lumps or consolidations along the colon. 
Thirst is intense, and there is complete anorexy. On ques- 
tioning, it is found that there has not been defalcation for 
several days. The treatment consists of purgatives, 
enemas, and milk diet. In the next few days the bowels 
are emptied freely, the abdominal pain ceases, the tempera- 
ture becomes lower, appetite is restored, and the patient 

Those who suffer from affections of the heart, liver, or 
kidneys are specially susceptible to the evil results of re- 
tained faecal matter. In such patients an error of diet or 
constipation may bring about most serious consequences. 

Such facts are well known to physicians, and it has been 
established that complete emptying of the lower bowels 
leads at once to favourable symptoms. From the other 
side, it has been shown by experiment that artificial reten- 
tion of the faeces by ligature of the rectum puts the body 
in a grave condition. 

If we collect our knowledge of all the facts, we cannot 
doubt but that the cause of the evil is multiplication of 

1 Accidents dus & la Constipation pendant la Grossesse, F Accouchement 
et les Suites des Conches. Thse, Paris, 1902, p. 32. 


microbes in the contents of the large intestine. When the 
faecal matter is free from microbes, as is the case with the 
meconium of the foetus or new-born infant, it is not a 
source of danger to the organism. The waste of cells and 
the secretions which are added to the undigested food 
cannot do any harm. Amongst the microbes of the gut, 
there are some that are inoffensive, but others are known to 
have pernicious properties. 

The ill-health which follows retention of faecal matter is 
certainly due to the action of some of the microbes of the 
gut. There are difficulties, however, in determining the 
precise mode of action of these microbes. It is generally 
believed that they form poisonous substances which are 
absorbed by the walls of the intestine and so pass into the 
system. The phrase auto-intoxication as applied to in- 
fants, women in labour, and patients affected with diseases 
of the heart, liver, or kidneys, is based on this interpreta- 
tion of the morbid processes involved. Attempts have been 
made to isolate and study the poisons in question, but there 
are many difficulties in the way. To distinguish between the 
actions of the poisons and of the microbes themselves, the 
latter have been destroyed by heat or by antiseptics, or been 
removed by filtration. Such methods, however, may alter 
the poisons and so are inconclusive. MM. Charron and 
Le Play l have tried to obtain exact results by heating the 
intestinal microbes to a temperature of about 136 Fahr., a 
process which probably does not seriously deteriorate the 
microbial poisons. Such material, injected into the veins 
of rabbits in large quantities, rapidly produced death, or in 
smaller quantities, proportionate ill-health. 

Kukula 2 has tried to produce this toxic action in animals, 

1 Comptes rendus de PAcademie des Sciences, Paris, 1905, 10 July, 
p. 136. a Archiv.f. klinische Chirurgie, 1901, vol. Ixiii, p. 773. 


employing microbial secretions obtained from cases of in- 
testinal obstruction. He succeeded in producing serious 
symptoms, such as vomiting and curvature of the neck 
and back, in fact, precisely the sequence of events familiar 
in cases of obstruction of the bowels or other retentions of 
faecal matter. 

Some of the products of the intestinal flora are un- 
doubtedly toxic, such as the benzol derivatives (phenol, 
etc.) ammonium and other salts. Many of these toxins 
have been insufficiently studied, but it is well known that 
certain of them can be absorbed by the wall of the gut and 
act as poisons. A well known case is the toxin of botulism 
which was isolated and studied by M. van Ermenghem. 1 
The poison, the product of a microbe which causes serious 
intestinal disturbance, is so fatal that a single drop given 
to a rabbit produces death after symptoms similar to those 
observed in cases of human beings poisoned by stale food. 
Butyric acid and the products of albuminous putrefaction 
are amongst the most pernicious of the microbial poisons 
produced in the large intestine. It is familiar that digestive 
disturbance is frequently associated with discharges of 
sulphuretted hydrogen and putrid excreta, and there is no 
doubt but that the microbes of putrefaction are the cause of 
these symptoms. 

It has been assumed for long that the retention of faecal 
matter tends to putrefactive changes in the intestines, and 
that the evil consequences of constipation are due to this. 
Recently, however, bacteriologists have criticised this 
accepted view, on account of the small number of microbes 
found in the excreta of constipated persons. Strasburger 
was the first to establish the fact, and his associate, Schmidt, 

1 Kolle u. Wassermann, Handb. d. pathogenen Mikro-organismen, vol. ii, 
1903, p. 678. 


showed that putrefaction did not follow when readily putre- 
scible substances were infected with material taken from 
cases of constipation. However, notwithstanding the 
exactness of these facts, I cannot accept the inference which 
has been drawn from them. The excreta discharged 
naturally in cases of constipation do not give a correct 
indication of the conditions inside the gut; whilst such 
matter contains few microbes, the substance removed after 
injection by an enema is extremely rich in bacteria. More- 
over, analysis of the urine, in cases of constipation, shows 
an excess of the sulpho-conjugate ethers which are 
known to be products of intestinal putrefaction. 

Not only is there auto-intoxication from the microbial 
poisons absorbed in cases of constipation, but microbes 
themselves may pass through the walls of the intestine and 
enter the blood. In the maladies that are the result of 
constipation some of the symptoms recall those of direct 
infection, and it is highly probable that, if special investiga- 
tions were made, microbes of intestinal origin would be 
found in the blood of the sick children and the pregnant 
or parturient women whose symptoms I have described 

The question as to the passage of microbes through the 
intestinal walls is one of the most controversial of bacterio- 
logical problems, and there is little agreement in the numer- 
ous publications regarding it. None the less, it is far from 
impossible to get a general idea of what goes on in an 
intestinal tract richly charged with microbes. 

Although the intestinal wall in an intact state offers a 
substantial obstacle to the passage of bacteria, it is incon- 
testable that some of these pass through it into the organs 
and the blood. Numerous experiments performed on dif- 
ferent kinds of animals (horses, dogs, rabbits, etc.) show 


that some of the microbes taken with food traverse the wall 
of the alimentary canal and come to occupy the adjacent 
lymphatic glands, the lungs, the spleen and the liver, 
whilst they are occasionally found in the blood and lymph. 
Discussion has taken place as to whether the passage takes 
place when the wall of the gut is absolutely intact or only 
when it is injured to however small an extent. It would 
be extremely difficult to settle the question definitely, but 
it is easy to see that it has little practical bearing. It is 
known that the wall of the gut is damaged extremely 
easily, so that the bluntest sound can hardly be passed into 
the stomach without making a wound through which 
microbes can pass into the tissues and blood. In the 
ordinary course of life, the delicate wall of the gut must 
often undergo slight wounding, and the frequent presence 
of microbes in the mesenteric ganglia of healthy animals 
shows clearly what takes place. 1 

It is indubitable, therefore, that the intestinal microbes 
or their poisons may reach the system generally and bring 
harm to it. I infer from the facts that the more a digestive 
tract is charged with microbes, the more it is a source of 
harm capable of shortening life. 

As the large intestine not only is the part of the digestive 
tube most richly charged with microbes, but is relatively 
more capacious in mammals than in any other vertebrates, 
it is a just inference that the duration of life of mammals 
has been notably shortened as the result of chronic poison- 
ing from an abundant intestinal flora. 

1 Ficker, in the Archiv. fur Hygiene, vol. Hi, p. 179, has recently 
published the results of an investigation into this. 



Relations between longevity and the intestinal flora Rumi- 
nants The Horse Intestinal flora of birds Intestinal 
flora of cursorial birds Duration of life in cursorial birds 
Flying mammals Intestinal flora and longevity of bats 
Some exceptions to the rule Resistance of the lower verte- 
brates to certain intestinal microbes 

IN the actual state of our knowledge it is impossible to 
make a final examination of my hypothesis, as there are 
many factors about which we are incompletely informed. 
Nevertheless, it is possible to confront the hypothesis with 
a large number of accurately established facts. 

Although the life of most mammals is relatively short, 
there are to be found in the group some which live rela- 
tively long, as well as others whose life is short. The 
elephant is an example of the long-lived mammals, whilst 
ruminants are short-lived forms. In the last chapter, I 
stated that sheep and cattle became senile at an early age, 
and did not live long. They are striking exceptions to the 
rule according to which the duration of life is in direct rela- 
tion with the size and length of the period of growth. The 
cow, which is much larger than a woman, and the time of 
gestation of which is about the same, or a little longer, 
acquires its teeth at four years old, and becomes senile at an 
early age ; it is quite old at between sixteen and seventeen, 


an age when a woman is hardly adult ; at the age of thirty, 
practically the extreme limit for bovine animals, a woman is 
in full vigour. 

The precocious old age of ruminants, the constitution of 
which is well understood, and which are carefully tended, 
coincides with an extraordinary richness of the intestinal 
flora. Food remains for a long time in the complicated 
stomach of these animals, and afterwards the digested 
masses remain still longer in the large intestine. Accord- 
ing to Stohmann and Weiske, 1 in the case of sheep it is a 
week until the remains of a particular meal have finally 
left the body of the animal. The excreta of sheep, normally 
solid, do not betray any special putrefaction in the intes- 
tine, but if the body is opened there is abundant evidence 
of the process. The intestinal contents are richly charged 
with microbes and give off a strong odour of putrefaction. 
It is not surprising that under these conditions, the life of 
sheep should be short. 

Another large herbivorous animal, the horse, also dies 
young, after a premature old age. Although it does not 
ruminate and possesses a simple stomach, the process of 
digestion is slow, and enormous masses of nutritive mate- 
rial accumulate in the huge large intestine. Ellenberger 
and Hofmeister 2 have shown that food remains in the 
alimentary canal for nearly four days. It remains in the 
stomach and the small intestine only 24 hours, but about 
three times as long in the large intestine. This is remark- 
ably different from what happens in the case of birds, in 
which there is no stagnation during the passage of food 
through the digestive canal. 

1 Quoted by Frddericq et Nuel, Elements de physiologic humaine, 4th 
edition, 1899, P- 2 5- 

2 Quoted by Fre"dericq et Nuel, op. cit. 


The structure of birds is adapted for flight, the body 
being as light as possible, many of the bones and the 
cavities of the body containing air-sacs. The absence of a 
bladder and of a true large intestine prevents the accumula- 
tion of excreta, these being ejected almost as rapidly as 
they are formed. The process of ejection, which takes 
place often in birds, is not so inconvenient as in mammals. 
The hind limbs are not used in flight, so that they offer 
no obstacle to evacuation. Thus birds may discharge their 
droppings while flying. 

Such structure and habits make it not surprising that 
the alimentary canal of many birds contains only a scanty 
intestinal flora. Parrots, for instance, which are remark- 
ably long-lived birds, harbour very few microbes in the 
intestine. The small intestine contains almost none, the 
rectum so few that the faecal matter appears to be formed 
of mucus, the waste of the food, and only a very few 
microbes. M. Michel Cohendy, who has examined the in- 
testinal flora at the Pasteur Institute, was unable to isolate 
more than five different species of microbes living in the 
alimentary canal of parrots. 

Even in birds of prey which feed upon putrid flesh, the 
number of microbes in the intestine is remarkably limited. 
I have investigated the case of ravens which I fed on flesh 
which was putrid and swarming with microbes. The drop- 
pings contained very few bacteria, and it was specially 
remarkable that the intestines had not the slightest smell of 
putrefaction. Although the opened body of a herbivorous 
mammal, such as a rabbit, gives off a strong smell of putre- 
faction, the body of a raven with the digestive tube exposed 
has no unpleasant smell. This absence of putrefaction in 
the intestine is probably the reason of the great longevity 
of such birds as parrots, ravens, and their allies. 


It might be said, however, that the long duration of life 
in birds is due to the organisation of these animals, rather 
than to the scantiness of their intestinal flora. To meet 
this objection, it is necessary to turn to the case of cursorial 

There are some birds incapable of flight, the wings of 
which are badly developed, but which have strong limbs, 
and can run with great rapidity. Ostriches, cassowaries, 
rheas, and tinamous, are well known examples of cursorial 
birds. They live on the surface of the ground, and their 
habits resemble those of mammals. When they are 
attacked by enemies, they escape by running so quickly 
that some of them (ostriches and rheas) outstrip even a 
horse. However, like mammals, they cannot discharge 
their secretions when they are running quickly. Tinamous 
(Rhynchotus rufescens), which I have observed in captivity, 
however quickly they may be running, stop abruptly to 
discharge their excretions. M. Debreuil, at my request, 
made observations on this matter, and assured me that the 
tinamous and rheas (Rhea americana) in his park always 
stood still for this purpose. He has noticed that the drop- 
pings, however abundant, were always deposited in heaps. 
With regard to ostriches, M. Riviere, director of the experi- 
mental Gardens at Hamma, Algeria, has been kind enough 
to give me the following information. " The discharge of 
excreta," he said in a letter in January, 1901, " is less 
frequent than in other birds, but the comparatively small 
size of the enclosures here makes it impossible for me to 
assert that the animal could discharge its droppings if it 
were running for a length of time ; a priori I should think 
that this did not happen. Normally the bird stands still 
for defaecation, the tuft of feathers on the tail is lifted up, 
and truere is a violent contraction of the abdominal muscles 


before the sphincters of the cloaca are suddenly opened to 
discharge the excrement with violence." 

I believe that the remarkable development of the large 
intestine in these running birds has been acquired to obviate 
the danger which is caused by the animal having to stop for 
defalcation. Although the huge caeca of these birds have 
a digestive function, particularly on plants rich in cellulose, 
I cannot think that the caeca of cursorial birds have been 
developed for digestion. As a matter of fact, some birds 
which are not cursorial live on the same kind of food 
(herbage, seeds, and insects) and have much smaller 

FIG. 14. Intestinal microbes from the caeca of a Rhea. 

caeca, the caeca indeed, in some, for instance, the pigeons, 
being quite rudimentary. 

It is not surprising that the accumulation of food mate- 
rial in the large intestine of running birds is associated with 
the presence of an extremely rich intestinal flora. Micro- 
scopic examination of the excrement of such birds shows 
this at once. Although the intestinal contents and excre- 
ment of many other birds show the presence of very few 
microbes, belonging to a small number of species, the same 
materials taken from running birds show enormous quan- 
tities of microbes, belonging to a large number of species. 
In the caecum of the rhea (Fig. 14) there are bacterial 


threads, spirilla, bacilli, vibrios, and many kinds of cocci. 
In the tinamous, the intestinal flora is if possible even 
richer. According to the statistical investigations of M. 
Michel Cohendy, the quantity of intestinal microbes in 
cursorial birds is not less than that found in mammals, even 
in man. 

If I am correct in the view that I have been explaining, 
cursorial birds, on account of their rich intestinal flora, 
ought to have a shorter duration of life than that of flying 
birds. I will now turn to this side of the question. Amongst 
cursorial forms, there are some of the largest living birds, 
ostriches being actually the largest living birds, whilst an 
extinct running bird, the Aepyornis of Madagascar, was 
the largest known bird. According to the rule that large 
animals live longer than small animals, ostriches should be 
able to reach a great age. The facts, however, are against 
this. M. Riviere, who rears ostriches in Algeria, and has 
a great experience of them, writes to me as follows : " I 
have no confidence in the stories about the longevity of the 
ostrich which were told me in the Sahara ; they rest on no 
facts. My personal observation is not very large, but it is 
quite exact. Some of the ostriches which have been hatched 
here have lived for 26 years. I do not estimate the duration 
of life of this bird at more than 35 years, and only one case 
of this age have I seen myself in 20 years. The bird was 
a female, a good layer and sitter; she died of old age, 
showing all the signs of decrepitude, the skin excoriated 
and lumpy, the feathers degenerate and dry. The bird laid 
eggs until nearly the end of her life, but at irregular inter- 
vals, and the shells were granular instead of being smooth 
and polished." 

In a farm near Nice, where ostriches are reared, there was 
recently an old male called " Kruger," which was supposed 


to be 50 years old. 1 Countess Stackelberg has been good 
enough to try to get information for me about this, and 
informs me that although they have not exact knowledge 
at the farm, they believe that it must be 50 years old. 
M. Riviere thinks this statement very surprising, and has 
nothing in his own long experience to confirm it. 

The facts which I have been able to get together do not 
attribute a long life to other running birds. Gurney men- 
tions that a cassowary (Casuarius westermanni) lived 26 
years in the Zoological Gardens of Rotterdam, and that 
three Australian emus (Dromacus novae-hollandiae) had 
lived in the same Gardens for 28, 22, and 20 years. M. 
Oustalet (Ornis, 1899, vol. x, p. 62) mentions another 
emu of the same species which died in London at the age of 
over 23 years. The rhea (Rhea americana), another large 
running bird, does not live so long. " Boecking thinks 
that its duration of life should be set down at from 14 to 15 
years. According to him, many of these birds die of old 
age " (Brehm, Oiseaux, vol. ii, p. 517). 

It is striking to compare the short life of cursorial birds, 
which nevertheless thrive and reproduce in captivity, with 
the remarkable longevity of so many other birds (parrots, 
birds of prey) which, although they are much smaller, 
have been kept alive for from 80 to 100 years. It would be 
difficult to find a more striking argument in favour of the 
view that richness of the intestinal flora shortens life. When 
birds become adapted to terrestrial life and acquire a huge 
large intestine in which microbes can abound, their dura- 
tion of life is diminished. 

Just as some birds, losing the aerial mode of life, have 
come to resemble mammals, so also some mammals have 

1 D aviculture (a fortnightly Russian journal), Oct. 1st, 1904, No. 19, 
P- 3- 


become flying animals, provided with wings and in some 
respects resembling birds. Bats are the most familiar in- 
stance. The large intestine, which is extremely useful to 
running animals, not only ceases to be an advantage but is 
harmful to flying creatures, insomuch as it increases the 
weight of the body uselessly. Bats, accordingly, have no 
caecum whilst the large intestine is changed in structure 
and function. Instead of being a capacious tube, serving 
as a reservoir for the refuse of the food, the large intestine 
of bats has the same diameter as the small intestine. Its 
structure is nearly identical. It is provided with glands, 
and as I have already mentioned in the last chapter, it 
digests the food in the same way as the small intestine. 
In fact, the large intestine has become simply a part of the 
small intestine, the total length of the gut being reduced. 
Bats, therefore, can no longer retain their secretions but 
have to empty the intestine almost as often as most birds. 
I find that Indian fruit bats (Pteropus medius) discharge 
their excreta very often. Microscopic examination shows 
that there is an absence of microbes quite unusual in the 
case of a mammal. The alimentary canal of bats is nearly 
aseptic, containing only a few single bacteria. I have fed 
these fruit bats with the same food (carrots) which I have 
given to rabbits, guinea pigs, and mice; whilst the bats 
accomplished the process of digestion in i| hours, and 
deposited excreta containing fragments of carrot, the 
rodents took very much longer for digestion and large 
quantities of waste matter accumulated in the caeca. The 
intestinal flora too, although the food in each case was the 
same, showed remarkable differences in these animals. It 
was almost absent in the bats, whilst in the rabbits, guinea- 
pigs and mice it consisted of a mass of microbes of different 
species. The excrement of the bats had no unpleasant odour, 
and the digestive canal of these bird-like mammals was free 


from putrefaction. Fruit bats fed upon fruit discharged 
excreta with a pleasant odour of apples and bananas. We 
have seen that birds which live a life similar to that of 
mammals acquire a rich intestinal flora and do not live so 
long as aerial birds. It would be extremely interesting to 
ascertain the duration of life of bats, mammals which live 
like birds and have a very scanty intestinal flora. I have 
been unable to get any exact information as to the duration 
of life of the true bats, that is to say, the insectivorous 
bats, as all the requests that I have addressed to specialists 
have proved fruitless. It appears, however, that it is a 
popular belief that bats live long. There is a Flemish 
phrase : " as long-lived as a bat," and a similar phrase is 
common in Little Russia. 

As for the fruit-eating bats, I have been able to ascertain 
that even in captivity, where the conditions are unfavourable 
to them, the duration of life is relatively long. I have had 
in my own possession a fruit bat (Pteropus medius) which 
was bought in Marseilles 14 years ago. It showed no signs 
of old age, and the teeth were in perfect condition. It died 
of some acute disease accidentally contracted. I know of 
another bat of the same species which lived in captivity for 
more than 15 years, and I have been informed that 1 in the 
London Zoological Gardens, a fruit bat has lived for 17 
years. If these bats were adult when caught, it would be 
necessary to add something to the known figures. 

Although I do not know the exact duration of the life of 
bats, it is clearly relatively long for mammals no bigger 
than guinea-pigs. The difference is remarkable if we com- 
pare it with the life of sheep, dogs and rabbits, mammals 
very much larger in size, but possessed of a rich intestinal 

The series of facts that I have been discussing strengthens 

3 Country Life, 1905. 



my conviction that the intestinal flora is an extremely im- 
portant factor in the causation of senility. It must not be 
supposed, however, that all the known facts can be ex- 
plained equally easily on this hypothesis. The harm done 
by microbes cannot always be measured by their abundance 
in the alimentary canal. In the first place, it must be 
remembered that some microbes are useful ; moreover, 
microbes, even although their products are very dangerous, 
may exist in quantities in an organism, and yet do no harm 
if the organism has the power of resisting bacterial poisons. 
Thus, for instance, the bacillus of tetanus, which thrives in 
the alimentary canal, and which can endanger life if the 
wall of the gut is wounded, does not harm a crocodile or a 
tortoise, as these animals are extremely resistant to the 
poison of tetanus. Dr. Favorsky, by experiments at the 
Pasteur Institute, has shown that the poison of botulism 
can be absorbed with impunity by some birds, and by tor- 
toises, although death follows if a very small quantity of it 
be introduced into the alimentary canal of a mammal. 

The bodies of man and of higher animals are possessed 
of a complex mechanism which resists the harmful action of 
bacteria and their poisons. The various parts of this 
mechanism may act differently, with the result that there is 
great variation in the power of resistance. Thus, however 
abundant microbes may be in the intestine, they may bring 
little harm to an organism that has a high power of destruc- 
tion or neutralisation of the toxins, or when these harmful 
products are unable to pass through the intestinal wall. It 
is in this way that I explain some exceptions to the general 
rule, which are exceptions only in appearance. Such a case 
is that of the nocturnal birds of prey. Although the diurnal 
birds of prey (eagles, vultures, etc.) have very short caeca, 
in which the food is never found, owls have very large 


caeca, which may be as long as 10 cm. (Eagle-Owl, Bubo 
maximus). These long caeca, however, contain debris of 
the food only in the enlarged terminal portion, and the 
food masses contain a very small number of microbes. 
Notwithstanding a great difference in the length of the caeca 
between the owls and the eagles, these two groups of birds 
do not differ greatly in longevity. But the difference in the 
caeca does not imply a corresponding difference in the intes- 
tinal flora which appears to be very scanty in both cases. 

It is possible that the elephant is a more real exception to 
the rule. Here is a case of a mammal with an enormous 
large intestine and a capacious caecum, and which none the 
less is capable of surviving for a century. I have had no 
opportunity of investigating the elephant from this point 
of view, and have no explanation to suggest. 

Monkeys and man differ from most mammals in so far as 
they possess a long duration of life, although their large 
intestines are very capacious. I have been unable to get 
exact information as to the longevity of monkeys, but I 
understand that these animals live longer than domesticated 
mammals, such as the ox, sheep, dog, and cat. Anthro- 
poid apes are supposed to be able to reach the age of 50 
years. The only other mammal with a longevity similar 
to that of the elephant is man. 

G 2 


Longevity of man Theory of Ebstein on the normal duration 
of human life Instances of human longevity Circumstances 
which may explain the long duration of human life 

MAN has inherited from his mammalian ancestors his 
organisation and qualities. His life is notably shorter 
than that of many reptiles, but longer than that of many 
birds and most other mammals. None the less he has in- 
herited a capacious large intestine in which a most abun- 
dant intestinal flora flourishes. 

Gestation and the period of growth are long in the human 
race, and from the point of view of theoretical considera- 
tions, human longevity should be longer than it generally 
is. Haller, a distinguished Swiss physiologist of the i8th 
century, thought that man ought to live to 200 years ; 
Buffon was of the opinion that when a man did not die 
from some accident or disease he would reach 90 or 100 

According to Flourens, man takes 20 years to grow and 
ought to live 5 times 20, that is to say, 100 years. 

The actual longevity is much below these figures, which 
arc based on theory. I have shown, moreover, that even 
if the rule based on the theory of growth can be accepted 
as generally true, it cannot be applied in every case, as the 
factors controlling duration of life are very variable. 


Statistics show that the highest human mortality occurs 
in the earliest years of life. In the first year after birth 
alone, one quarter of the children die. After this period 
of maximum mortality, the death-rate slowly falls until 
the age of puberty, and then rises again slowly and con- 
tinuously. It reaches a second maximum between the ages 
of 60 and 75, and then slowly falls again to the extreme 
limit of longevity. 

Bodio, 1 an Italian man of science, holds the view that 
the great mortality of infants is a natural adaptation to 
prevent too great an increase of the human race. This 
view, however, cannot be supported, and rational hygiene 
readily brings about a great diminution in the mortality of 
children. The cause of mortality is in most cases maladies 
of the intestinal canal, produced by erroneous diet, and 
with the advance of civilisation, infant mortality has been 
very greatly reduced. 

I find it impossible to accept the view that the high 
mortality between the ages of 70 and 75 indicates a natural 
limit of human life. As a result of investigations into 
mortality in most of the European countries, Lexis came 
to the conclusion that the normal duration of human life 
was not more than 75 years. Dr. Ebstein c accepts this 
statistical result and announces that " we now know the 
normal limit set by nature to the life of mankind. This 
limit is at the age of maximum mortality. If man dies be- 
fore then, his death iz premature. Everyone does not 
reach the normal limit; life ends generally before it, and 
only in rare cases after it." 

The fact that many men of from 70 to 75 years old a*re 
well preserved, both physically and intellectually, makes 

1 Quoted by Ebstein, Die Kunst d. mensch. Leben zu verlcingern, 1891. 

2 Op. tit., p. 12. 


it impossible to regard that age as the natural limit of 
human life. Philosophers such as Plato, poets such as 
Goethe and Victor Hugo, artists such as Michael Angelo, 
Titian and Franz Hals, produced some of their most 
important works when they had passed what Lexis* and 
Ebstein regard as the limit of life. Moreover, deaths of 
people at that age are rarely due to senile debility. In 
Paris, for instance, in 1902, of cases of deaths between the 
ages of 70 and 74, only 8*5 per cent, were due to old age. 1 
Infectious diseases, such as pneumonia, tuberculosis, dis- 
eases of the heart and the kidneys, and cerebral 
haemorrhage, caused most of the deaths of these old people. 
Such cases of death, however, can often be avoided and 
must be regarded as accidental rather than natural. 

Confirmation of the view that the natural limit is not at 
70 to 75 years is to be found in the fact that so many men 
reach a greater age. Centenarians are really not rare. In 
France, for instance, nearly one hundred and fifty people 
die every year, after having reached the age of looor more. 
In 1836, in a population of thirty-three millions and a half 
(33,540,910), there were 146 centenarians, that is to say, one 
in about 220,000 inhabitants. In some other countries, 
particularly in Eastern Europe, the number of centenarians 
is still greater. In Greece, for instance, there is a centen- 
arian for each set of 25,641 living persons, that is to say, 
nine times as many as in France. 2 

What age can be reached by the human species ? For- 
merly it was supposed that individuals might live for 
several centuries ; to say nothing of Methuselah, whose age 
of 969 years, mentioned in the Bible, is the result of a 
mistake in calculation, I may mention Nestor, who, accord- 

1 Annuaire statistique de la -ville de Paris, 23rd year, 1904, p. 164-171. 

2 Ornstein, Virchow's Archiv., 1891, vol. cxxv, p. 408. 


ing to Homer, lived for three human ages, that is to say, 
300 years, or Dando, the Illyrian, and the King of the 
Lacmons, who were supposed to have reached ages of five 
or six centuries. These ancient records are, of course, quite 
incorrect. Much more confidence can be placed in some 
facts relating to more modern times, according to which 
the extreme old age reached by man was 185 years. 
Kentigern, the founder of the Cathedral of Glasgow, 
known by the name of St. Mungo, died at the age of 185, 
on Jan. 5th, 6OO. 1 Another astonishing case of longevity 
is related from Hungary, where an agriculturist, Pierre 
Zortay, born in 1539, died in 1724. The Hungarian 
records of the i8th century contain other cases of death at 
ages between 147 and 172 years. 

The case of Drakenberg is still more authentic ; he was 
born in Norway in 1626 and died in 1772, at the age of 
146. He was known as the Old Man of the North. He 
had been captured by African pirates and was held by 
them for fifteen years, and was engaged as a sailor for 
ninety-one years. His romantic history attracted contem- 
porary attention, and the journals of the time (Gazette de 
France, 1764, Gazette d'Utrecht, 1767, etc.) 2 contain in- 
formation regarding him. The well-known instance of 
Thomas Parr appears to rest on good authority. Parr was 
a poor Shropshire peasant, who did hard work until he was 
130 years old, and who died in London at the age of 152 
years and 9 months. The celebrated Harvey examined 
the body after death and was unable to discover organic 
disease ; even the cartilages of the ribs were not ossified and 
were elastic as in a young man. The brain, however, ^-as 
hard and resisting to the touch, as its blood-vessels were 

1 Ebstein, op. '/., p. 70. 

2 Lejoncourt, Galerie des centenaires^ Paris, 1842, p. 96-98. 


thickened and dry. Parr was buried in Westminster 
Abbey. 1 

It appears, then, that human beings may reach the age 
of 150, but such cases are certainly extremely rare, and 
are not known from the records of the last two centuries. 
I cannot accept without a good deal of reserve the state- 
ments as to two persons who died in the beginning of 
the igth century at the ages of 142 and 145. On the other 
hand, cases of duration of life from 100 to 120 years are 
not very rare. 

Extreme longevity is not limited to the white races. 
According to Prichard, 2 negroes have lived respectively 
to 115, 160, and 180 years. In the course of the igth 
century there have been observed, in Senegal, eight negroes 
ranging from 100 to 121 years old. M. Chemin 3 saw 
himself in 1898 at Foundiougne an old man, whom the 
natives stated to be 108 years of age; although he was 
in good health, he had been blind for several years. The 
same author, on the authority of the New York Herald 
of June I3th, 1895, mentions the case of a coloured woman 
in North Carolina, who was more than 140 years old, and 
of a man 125 years old. 

Women more frequently become centenarians than 
men, although the difference is not very great. For in- 
stance, in Greece, in 1885, in a population of nearly two 
millions (1,947,760), there were 278 persons aged from 
95 to 1 10 years, of whom 133 were male and 145 female. 

1 Lejoncourt, op. tit., p. 101. 

2 Researches into the Physical History of Mankind, 1836, vol. i, p. 1 157. 

3 I owe to the kindness of M. Chemin a memoir in which he has 
brought together the ancient and new records on the centenarians of all 
countries up to the end of the nineteenth century. M. Chemin was 
unable to find a publisher, but has given me his manuscript, extending to 
182 pages. 


In the seven years, from 1833 to 1839 inclusive, according 
to Chemin, there were in Paris twenty-six men over the age 
of 95, and forty-five women. Such facts, and many others, 
support the general proposition that male mortality is 
always greater than that of the other sex. 

In most cases centenarians are notably healthy and of 
strong constitution. There are instances, however, of 
abnormal people having reached a great age. A woman, 
called Nicoline Marc, died in 1760, at the age of no. 
Since she was two years old, her left arm was crippled. 
Her hand was bent under the arm like a hook. She was 
a hunch-back, and so bent that she appeared to be no 
more than four feet high. A Scotch woman, Elspeth 
Wilson, died at the age of 115 years. She was quite a 
dwarf, being only a little over two feet high. On the other 
hand, although they usually have a very short life, giants 
have been known to reach the age of 100. 

Haller, in the eighteenth century, remarked that centen- 
arians often occurred in the same family, as if longevity 
were a hereditary quality. It is certainly the case that the 
descendants of centenarians frequently reach extreme age. 
Thomas Parr, for instance, left a son who died in 1761, 
at the age of 127 years, having retained his mental facul- 
ties until death. In M. Chemin's list of centenarians, 
there are eighteen cases of extreme old age having been 
reached by their relations. As all innate characters can be 
transmitted, the influence of heredity and longevity must 
be admitted. At the same time, it is necessary to remem- 
ber the important influence of the similarity of conditions 
in the case of parents and children. Many cases of tuber- 
culosis and leprosy, which used to be assigned to heredity, 
are now known to be due to infection in the same condi- 
tions of life, and some of the examples of the attaining 


of a great age by more than one member of a family may 
be explained by the influence of surrounding circum- 
stances. Very frequently the husband and wife, although 
not related by blood, both attain extremely advanced age. 
I found 22 cases of this kind in M. Chemin's list; I will 
give a few of them. A widow, Anne Barak, died at the 
age of 123, in Moravia; her husband died at the age of 
118. In 1896, there was alive in Constantinople, M. 
Christaki, a retired army doctor of the age of no; his 
wife was 95 years old. In 1886, M. et Mme. Gallot, aged 
respectively 105 years and 4 months, and 105 years and 
one month, died within two days of each other at Vaugirard, 
54, Rue Cambronne. Lejoncourt mentions a South 
American of 143 years old, whose wife had lived to the 
age of 117. 

It is worth enquiring if there be any relation between 
longevity and locality. There are some countries in which 
very many of the natives reach old age. It appears that 
Eastern Europe (Balkan States, and Russia), although 
its civilisation is not high, contains many more centen- 
arians than Western Europe. I have already mentioned 
that Dr. Ornstein had shown the existence of many ex- 
tremely old people in Greece. M. Chemin states that 
in Servia, Bulgaria and Roumania there w'ere more than 
5,000 centenarians (5,545) living in 1896. " Although 
these figures appear to be exaggerated," wrote M. Chemin, 
"it is undoubtedly the case that the pure and keen air of 
the Balkans, and the pastoral or agricultural life of the 
natives, predisposes to old age." The same author men- 
tions several localities in France, notable for the numbers 
of very old people. In 1898 in the commune of Sournia 
(Pyrenees-Orientales) the total population was 600, 
amongst which there was one woman of 95 years, a man 
of 94, a woman of 89, two men of 85, two of 84, and two of 


83, three women of 82, and two men of 80. At St. Blimont 
in the Department of the Somme, amongst the 400 inhabi- 
tants alive in 1897, there were six men between the ages of 
85 and 93 years and one woman in her loist year. 

It cannot be accepted that it is the keen air which 
lengthens the life, because Switzerland, a mountainous 
country, is notable for the rarity of centenarians. It is 
more likely that some circumstance in the mode of living 
influences longevity. 

It has been noticed that most centenarians have been 
people who were poor, or in humble circumstances, and 
whose life has been extremely simple. There are instances 
of rich centenarians, such as Sir Moses Montefiore who 
died at the age of 101, but such are extremely rare. It may 
well be said that great riches do not bring a very long life. 
Poverty generally brings with it sobriety, especially in 
old age, and it has been often said that most centenarians 
have lived an extremely sober life. They have not all 
followed the example of the celebrated Cornaro, who 
brought himself to subsist on a daily diet of no more 
than twelve ounces of solid food, and fourteen ounces of 
wine, and who, although his constitution was weak, lived 
for about a century. He has left extremely interesting 
Memoirs, and retained his intelligence until his death on 
the 26th April, 1566 (Lejoncourt, p. 146). 

In M. Chemin's list I have counted twenty-six centen- 
arians, distinguished by their frugal life. Most of them 
did not drink wine, and many of them limited themselves 
to bread, milk and vegetables. 

Sobriety is certainly favourable to long life, but it is' 
not necessary, because quite a number of centenarians have 
drunk freely. Several of those who are catalogued by 
Chemin, drank wine and spirits even to excess. Catherine 
Reymond, for instance, who died in 1758 at the age of 107 


years, drank much wine, and Politiman, a surgeon who 
lived from 1685 to 1825, was in the habit, from his twenty- 
fifth year onwards, of getting drunk every night, after 
having attended to his practice all day. Gascogne, a butcher 
of Trie (Hautes-Pyrenees), died in 1767 at the age of 120, 
and had been accustomed to get drunk twice a week. A 
most curious example is that of the Irish land-owner 
Brawn, who lived to the age of 120, and who had an in- 
scription put upon his tombstone that he was always 
drunk, and when in that condition was so terrible that 
even death had been afraid of him. Some districts, even, 
are distinguished at once for the longevity of their in- 
habitants and for the large local consumption of alcohol. 
In 1897, tne village of Chailly in the Cote-d'Or had no 
less than twenty octogenarians amongst 523 inhabitants. 
This village is one of the localities in France where most 
alcohol is consumed, and the old people are very far from 
being distinguished from their younger fellows by any 
special sobriety. 

In some cases centenarians have been much addicted to 
the drinking of coffee. The reader will recall Voltaire's 
reply when his doctor described the grave harm that 
comes from abuse of coffee which acts as a real poison. 
" Well," said Voltaire, " I have been poisoning myself for 
nearly 80 years." There are centenarians who have lived 
longer than Voltaire, and have drunk still more coffee. 
Elisabeth Durieux, a native of Savoy, reached the age of 
114. Her principal food was coffee, of which she took daily 
as many as forty small cups. She w^as jovial and a boon 
table companion, and used black coffee in quantities that 
would have surprised an Arab. Her coffee-pot was always 
on the fire, like the tea-pot in an English cottage (Lejon- 
court, p. 84; Chemin, p. 147). 

It has been noticed that many centenarians do not smoke, 


but this like all other traits is not universal. M. Ross, 
who gained a prize for longevity in 1896 at the age of 102, 
was an inveterate smoker. In 1897, a widow named 
Lazennec, died at La Carriere, in Kerinou, Finistere, at 
the age of 104. She lived in a hovel on charity, and she 
had smoked a pipe ever since she was quite young. 

It is plain that any factor to which long duration of life 
has been attributed disappears when many cases are 
examined. Naturally a sound constitution and a simple 
and sober life are favourable to longevity, but apart from 
these, there is something unknown which tends to long 
life. The celebrated physiologist of Bonn, Pfliiger, 1 came 
to the conclusion that the chief condition of longevity is 
something " intrinsic in the constitution," something which 
cannot be defined exactly, and which must be set down to 

In the present state of knowledge, we cannot denote the 
chief cause of human longevity, but the proper course 
will be to seek it out as we would seek out that of animal 
longevity. As human longevity is often local in its charac- 
ter, and is exhibited by married people who have nothing in 
common except their mode of life, we may enquire into the 
intestinal flora and the mechanism by which the organism 
resists its harmful effect as factors which influence the 
duration of life. It is reasonable to suppose that in persons 
living in the same district or under the same roof, the in- 
testinal flora may be similar. The problem can be settled 
only by a series of laborious researches which have yet to 
be made. At present I can do no more than bring together 
a large number of facts regarding the duration of life in 
man and in animals, with the hope of suggesting the lines 
for future investigation. 

1 Ueber die Kunst d. Verlangerung d. mensch. Lebens, Bonn, 1890, p. 23. 




Theory of the immortality of unicellular organisms Exam- 
ples of very old trees Examples of short-lived plants Pro- 
longation of the life of some plants Theory of the natural 
death of plants by exhaustion Death of plants from auto- 

IT must surprise my readers to find how little science really 
knows about death. Although death has a preponderating 
place in religions, systems of philosophy, literature and 
folk-lore, scientific works pay little attention to it. This 
unfortunate fact explains, although it may not justify, the 
bitter attack made on science on the grounds that it is 
occupied with minutiae and neglects the great problems of 
human life, such as death. When Tolstoi was absorbed by 
the problem and searched for some solution in the writings 
of scientific men, he found that the explanations were trivial 
or inexact. In consequence he was extremely indignant 
with the men who devoted themselves to the investigation 
of what seemed to him useless problems (such as the insect 
world, or the structure of cells and tissues) and who were 
yet unable to say what the destiny of man or death might be. 
I am far from claiming to solve these problems ; I can do 
little more than describe the actual state of the question of 
natural death. I hope in this way at least to prepare for 


scientific investigation, and to call attention to it as the most 
important problem of humanity. 

By the use of the phrase " natural death " I mean to 
denote a phenomenon that is intrinsic in the nature of an 
organism and that is not the mere result of an external acci- 
dent. Popular phraseology includes under natural death 
all cases due to diseases. But as such deaths can be avoided 
and are not due to qualities inherent in the organism, it is 
erroneous to include them in the category " natural death." 

In nature, death comes so frequently by accident that 
there is justification for asking if natural death really oc- 
curs. It used to be thought that death was the inevitable 
end of life and that the living principle contained within 
itself the germ of death. Accordingly, it was a surprising 
discovery that many low organisms die only by accident, 
and that if such accident be avoided, death does not fall on 
them. Unicellular organsims (such as infusoria, many 
other protozoa and low plants) multiply by simple division, 
the organism thus giving rise to two new organisms ; the 
parent so to speak loses itself in its offspring without under- 
going death. To criticisms of this mode of presentment 
of the facts, Weismann, who has attracted most attention 
to the view, replied as follows : "In cultures of Infusoria, 
these little animals continually multiply by division and no 
dead bodies are found* The individual life is short, but it 
ends not in death but in transformation to two new indivi- 

Max Verworn, 1 a physiologist of repute, objected that 
Weismann had overlooked the occurrence within the organ- 
ism of a process of partial destruction, and that under cer- 
tain conditions a complete organ of the infusorian body (the 
nucleus) dies and is absorbed. Such death of a part, how- 
ever, is not followed by death of the whole, and as the 

1 Physiologic g/ntrale, 1900, p. 381. 


continuous destruction of some of the cells in our own 
bodies is not regarded as our death, the criticism of the 
German physiologist cannot be accepted. 

It is not only the extremely short-lived microscopic organ- 
isms that escape death. Some of the higher plants, which 
may attain to gigantic size, encounter death only by acci- 
dents. There is nothing to be found in the nature of their 
organisation which would seem to indicate that death is the 
inevitable or even probable result of their constitutions. 

The longevity of some trees has long been notorious, as 
these appear to live for many centuries and to die only 
when they are overwhelmed by the ravages of a storm or 
killed by human agency. 

When the Canary Islands were discovered, in the begin- 
ning of the fifteenth century, the early explorers were struck 
with the gigantic size of a dragon tree which was venerated 
by the natives as their tutelary deity. The tree stood in 
a Garden at Orotava in Teneriffe, and even in these early 
days, its huge trunk contained a gigantic hollow. The tree 
did not reward the worship of the natives, who were anni- 
hilated by the Spaniards, and it survived them for nearly 
four centuries. At the end of the eighteenth century it was 
seen by Humboldt, 1 who found that the trunk was forty- 
five feet in circumference, and who attributed to it a great 
age because dragon trees grow extremely slowly. Early in 
the nineteenth century (1819) a furious tempest swept over 
Orotava and with a gigantic crash nearly a third of the 
crown of leaves and branches fell on the ground. Notwith- 
standing this shock, the monster survived for fifty years. 
Berthelot, 2 who visited it in 1839, described it as follows : 
" A dragon tree stood in front of my dwelling, grotesque in 

1 Tableaux de la nature (French translation), 1808, vol. ii, p. 109. 
* Webb and Berthelot, Histoire naturelle des ties Canaries, 1839, vol. i, 
part 2, pp. 97-98. 


form, gigantic in size, which a storm had smitten without 
overwhelming. Ten men would have much ado to girdle 

FIG. 15. The Dragon-tree of the villa Orotava. 

its vast trunk, fifty feet in circumference at the ground. 
The huge column had a deep cave within it, hollowed by 
the ages; a rustic porch gave access to the interior, and the 



lofty dome, although half had been destroyed by a storm, 
still bore an enormous crown of branches." 

The famous dragon-tree got more and more damaged, 
and was finally overthrown by a storm in 1868. A few 
years after the catastrophe (in 1871) I myself saw the 
remains of the colossus, lying on the ground as a huge 
grey mass like some antediluvian monster. No accurate 
estimate of its age can be formed, but it must have lived 
several thousand years. 

Trees have been known which were still older than the 
dragon-tree of Teneriffe. One of the best known is the 
baobab of Cape Verd, described by Adanson. " This re- 
markable tree was thirty feet in diameter when the famous 
French naturalist measured and described it. Three centu- 
ries earlier, some English sailors had cut an inscription on 
it, and Adanson laid this bare by removing three hundred 
layers of wood. On his observations Adanson based an 
estimate of 5,150 years as the age of the tree. 1 The old 
cypresses of Mexico are thought to be still older. A. de 
Candolle 2 concluded that the cypress of Montezuma was 
2,000 years old when he saw it, and that the cypress at 
Oazaca was much older than the tree described by Adan- 
son. In California, trees of the species Sequoia gigantea 
are three thousand years old, and Sargent, an American 
botanist, attributes to some of them an age of at least five 
thousand years. 

The question of the nature of individuality in the vege- 
table world has been raised in connection with the longevity 
of trees. It has been asked if a tree is to be regarded as a 
single individual or as a colony of many plants like a 
branching polyp. It is a difficult question, but only of 

1 Bibliotheque universelle de Geneve, 1839, vol. xlvi, p. 387. 

2 Ibid., p. 392. 


secondary importance from the point of view of this dis- 
cussion. A. de Candolle, 1 having paid special attention to 
the subject, came to the conclusion that trees do not die of 
old age, that, in the real sense of the phrase, there is no 
natural end of their existence. Many botanists agree with 
him. Naegeli 2 holds that a tree several thousand years old 
dies only from external accidents. 

It is plain that amongst the lower plants and the higher 
plants there are cases where natural death does not exist. 
Theoretically, life would have an unlimited duration, sub- 
ject to the continuous replacement of the substance of the 
organism in the normal metabolism. It must not be 
inferred, however, that there is no such occurrence as 
natural death amongst plants. There are numerous cases 
where death comes quite apart from the agency of external 
forces. Even amongst closely related plants there are some 
cases where natural death does not occur, and others where 
it is normal. The lower fungi offer a good instance. Some 
of these pass through a longer or shorter vegetative stage 
and then the living mass breaks up into spores (Myxomy- 
cetes). The whole bulk of matter is not transformed, but 
the remnant consists only of cuticular secretions, not living 
cells. In other fungi, only some of the cells transform to 
spores, the others dying naturally. 

One stage of the life history of some lower plants is of 
short duration. The prothalli of some cryptogams (Mar- 
siliace<B) live only a few hours, just long enough for the 
appearance of the sexual organs. When these are ripe 
the body of the prothallus and all its constituent cells fall 
a prey to natural death. In such cases there is a " corpse," 

1 Bibliotheque universelle de Geneve, vol. xlvii, p. 49. 

2 Entstehung u. Begriff d. naturhistorischen Art, 2nd edit., Munich, 
1865, p. 37. 

II 2 


composed of dead cells and protoplasm. Even amongst the 
higher plants there are instances of an extremely short dura- 
tion of life. Amaryllis lutea passes through all the stages 
of its life-history in ten days, the minimum time necessary 
for the sprouting of the leaves and flowers and the produc- 
tion of the seeds, after which it dies naturally. 1 It is inter- 
esting to find that in the same family there are other plants 
notable for long duration of life. The Agave requires a 
century to produce its flowers before death comes naturally. 

Everyone is familiar with the so-called " annual " plants 
which live only a few months, from the time when they 
sprout, until, after the production of seed, death comes to 
them naturally. The life of annuals, however, can be pre- 
served for two or for several years. Rye is normally an 
annual, but some varieties are able to live for two years and 
produce two crops. The Cossacks of the Don have estab- 
lished this fact, and have cultivated a biennial variety of 
rye for many years. 2 Beetroot 3 is normally biennial, but 
has been changed to a plant which lives for from three to 
five years. Such instances are by no means unique. 

Natural death can be postponed if the plant be prevented 
from seeding. Professor Hugo de Vries has prolonged the 
life of the Oenotheras he cultivates, by cutting the flowers 
before fertilisation. Under ordinary conditions the stem 
dies after producing from forty to fifty flowers, but, if cut- 
ting be practised, new flowers are produced until the winter 
cold intervenes. By cutting the stem sufficiently early, 
the plants are induced to develop new buds at the base, and 
these buds survive winter, and resume growth in the fol- 

1 Griesebach, Die Vegetation der Erde. 

2 Batalin, A eta Horti Petropolitani, vol. xi, no. 6, 1890, p. 289. 

3 I am indebted to Prof. Hugo de Vries for this and other instances of 
the prolongation of life in plants. 


lowing spring." (Extract from a letter of Prof. H. de 

The grass of lawns is usually mowed before it begins to 
flower, so as to prevent the ripening of the seeds and the 
death of the plant. When this is done, the grass remains 
continually green, and its life lasts for several years. 

The connection between the seeding of plants and their 
natural death has been recognised for long, and is usually 
explained as being due to the exhaustion of the plant. 

As I am not a botanist, and was anxious to know the 
views of botanists on natural death, I wrote to Prof, de 
Vries, as a universally accepted authority. The distin- 
guished botanist replied to me as follows. " Your question 
is extremely difficult. I do not think that much is known 
as to the exact cause of the death of annual plants, but it is 
customary to attribute it to exhaustion." All the botanists 
who have expressed opinions on this matter appear to 
hold a similar view. Hildebrand, 1 the author of a memoir on 
the duration of life in plants, stated this view again and 
again. According to him " the life of annuals is usually 
short because they are exhausted by their extensive produc- 
tion of seeds (p. 116)." "Even amongst plants which pro- 
duce seeds for several years, there are some which are pre- 
maturely exhausted by fructification and which die spon- 
taneously " (p. 67). In the prothallus of many of the 
higher cryptogams, the formation of a single embryo is 
followed by natural death ; as Goebel 2 points out, the 
embryo completely absorbs the prothallus. 

As plants generally obtain their food with ease, it is 
natural to ask what is the cause of the exhaustion after* 
seeding. When a plant which cannot resist cold dies after 
it has produced its seeds in the end of the summer, the event 

1 Engler's Botanische Jahrbiicher, Leipzig, 1882, vol. ii, p. 51. 

2 Organog raphie der Pflanzen, Idna, 1898-1901. 


is natural enough. But how can \ve explain the death of an 
annual plant which is growing in a rich soil, and which seeds 
in the beginning of the summer, as being due to exhaustion 
long before the winter cold. It frequently happens that 
after harvest new shoots spring up from grains which have 
fallen. The soil which can support this new vegetation 
cannot have been exhausted by the cereal in question ; and 
there has been enough warmth for the new crop. It cannot 
be the external conditions which have caused the death of 
the parent plant. The explanation of this apparent contra- 
diction has been sought in the constitution of the plant 
itself. Hildebrand remarks that " certain species have a 
constitution which tends to early fructification. As soon as 
the seeds have been set, the strength of the plant is ex- 
hausted in the swelling of the grains, so that the plant 
dies." " Other species, on the contrary, are so constituted 
that they vegetate for a long time, before fruiting, after 
which, however, they also die. A third set of plants have 
such a constitution that " they do not die after seeding, 
that they can seed often and live for many years " (p. 113). 
Being unable to indicate exactly the intrinsic mechanism 
of these different "constitutions," several botanists ex- 
plain them by a kind of teleological predestination. 
According to Hildebrand "the nutritive processes of a 
plant have no other purpose than to make it capable of 
reproduction ; this final end, however, can be reached in 
different modes and after different periods of time" (p. 
132). Goebel sets down similar views. "In heterosporous 
plants the whole course of the development of prothalli 
is predetermined. The prothalli, so far as we actually 
know, to use the phrase of theologians, are predestined; 
their fate is determined once for all " (p. 403). M. Massart l 
expresses the same kind of view, when he says that " some- 
1 Bulletin dtt jardin botanique de Bruxelles, vol. i, no. 6, 1905. 


times cells die because their work is finished, and they have 
no longer any reason for existing." 

Such an interpretation of the facts is quite opposed to 
determinism, and makes the problem of natural death in 
the plant world more difficult but more interesting. 

The modern scientific conception of the universe excludes 
the idea of predestination. The relations between fructifi- 
cation and natural death must be regulated by the law of 
selection, according to which no organism survives if its 
reproduction is impossible. It occasionally happens that 
children are born without organs which are indispensable 
to life. Such monsters of different kinds being non-viable, 
cannot be said to be predestined to death, as they die 
because of defects in their structure. Others are born with 
all that is necessary for life, and survive for that reason, 
not because they are predestined to life. So also species 
of plants which develop incompletely and which die before 
they have produced spores or seeds, cannot survive ; whilst 
those which die after having given birth to the next genera- 
tion survive in their descendants. However quickly death 
follow the production of seed, the species will survive 
equally well. The cause of the natural death of plants 
must be sought, therefore, not in predestination, but in 
the mechanism of the organic processes. 

Nothing seems more probable than that a plant should 
die when all its organic forces have been exhausted. It 
would be interesting, however, to ascertain the mechanism 
of that exhaustion, and this especially because it is often 
very difficult to imagine a cause for it. Many plants exist 
which produce several generations each season, in the same 
soil, without exhausting it. In perennial plants, some parts, 
such as the flowers, die periodically, although the plant 
itself is not exhausted. Everyone has seen that in gera- 


niums some of the flowers wither whilst others are bloom- 
ing, the process going on throughout the season. We can 
scarcely attribute such a natural death of the flowers to any 
exhaustion of the plant which continues to produce new 

The fairly frequent prolongation of the life of plants is 
also out of harmony with the theory of natural death as the 
result of exhaustion. It sometimes happens that male 
plants produce female flowers abnormally ; cases of this 
kind have been observed in willows, stinging-nettles, hops, 
and especially in maize. 1 Here we have to deal with a 
kind of monstrosity, differing, however, from the non- 
viable monsters of the human race, in the respect that the 
production of female flowers on the male branches results 
in the prolongation of their lives. Generally the male 
branches die a natural death as soon as the pollen has been 
shed, and therefore some time before the death of the 
female flowers. If, however, a male branch bears a female 
flower which becomes fertilised, then the life of the branch 
is prolonged until the seeds ripen. If the natural death of 
the male flowers is the result of exhaustion due to the 
development of the pollen, how can we reconcile this with 
the prolongation of life in a case where the male branch 
has also female flowers to nourish and seeds to mature ? 

It is quite clear that natural death, in such cases, is the 
result of a mechanism more complex than simple ex- 

Prof, de Vries has already noted that the duration of life 
in plants depends on their vital processes. That view im- 
plies that there are some qualities inherent in its organisa- 
tion which can prolong or shorten the life of a plant, and it 

1 Hugo de Vries, Jahrbiicher fiir wissensch. Botanik, 1890, vol. xxii, 
p. 52. 


is here that we ought to find the key to the problem of 
natural death in the vegetable world. However, to gain 
exact knowledge of such factors, it would be necessary to 
have information on many points in plant physiology 
which unfortunately are very imperfectly known. In this 
respect, the vital conditions of the simplest plants, such 
as yeasts and bacteria, have been investigated much more 
fully. It is true that such low organisms reproduce freely 
either by division or by budding, so that they are amongst 
the organisms in which natural death is not inevitable. 
None the less, in their lives phenomena occasionally present 
themselves which can be interpreted as cases of natural 

At a time when it was still unknown that all fermenta- 
tion was due to the action of microscopic plants, it had 
been observed that, in certain conditions, fermentation 
ceased much more quickly than in other conditions. For 
instance, when sugar is being transformed to lactic acid, 
it is useful to add chalk, as otherwise the fermentation stops 
before the greater part of the sugar has been acted upon. 
When, in 1857, Pasteur made his great discovery of the 
lactic acid microbe, he showed that that little organism, 
although it could produce lactic acid, was interfered with 
by an 'excess of the acid. To secure complete fermenta- 
tion, it was necessary to neutralise the acid by the addition 
of chalk. 

When the action of lactic acid is continued too long, it 
not only arrests the process of fermentation but definitely 
kills the microbe. It is for that reason that it has been 
found difficult to preserve the lactic acid ferment for a long- 
time in a living condition. Amongst the ferments which 
have been isolated from Egyptian ' leben ' by MM. Rist 
and Khoury 1 there is one which is extremely delicate. 
1 Annales de flnstitut Pasteur, 1902, p. 71. 


When it is inoculated deep in a nutritive medium, it dies 
in a few days, death, without doubt, being due to the 
lactic acid produced by the microbe from the sugar and 
not neutralised. As this transformation of sugar into 
lactic acid is a fundamental property of the microbe, de- 
pending on its constitution, the arrest of the fermentation 
and the death of the ferment in these definite 'Conditions 
can be interpreted only as natural death due to auto-intoxi- 
cation, that is to say to poisoning by a product of the 
physiological activity of the microbe itself. As death 
takes place at a time when the medium still contains 
enough sugar for the nutrition of the microbe, it is certain 
that it cannot be the result of exhaustion. This case of 
the lactic acid ferment is not unique. The microbe which 
produces butyric acid is also interfered with by the acid 
it secretes. M. G. Bertrand, who has examined carefully 
the microbe which produces fermentation in sorbose (sugar 
extracted from fruit of the service-tree) (Sorbus domestica) 
has informed me that this fermentation, too, ceases under 
the influence of the secretions of the microbes, and that 
the microbes undergo natural death at a time when the 
medium is far from exhausted of the nutritive material. 
The yeast which produces alcohol is also interfered with 
by an excess of alcohol, and as soon as a certain limit 
of alcoholic strength has been reached, fermentation stops. 
When the yeast is grown in media rich in nitrogen and 
poor in sugar, the plant takes the nitrogenous material 
and produces salts of ammonia. These alkalies damage 
the yeast and cause its death by auto-intoxication. 1 

In the examples that I have given, natural death was 
a result of the activity of the microbes, and was in cor- 
relation with their organisation. Such death can be 
1 Duclaux, Microbiologie, vol. iii, 1900, p. 460. 


avoided by changing the external conditions, and, if the 
acids or alkalies produced by these bacteria are neutralised, 
the bacteria survive. The facts are in harmony with those 
that I described in the case of the higher plants. By pre- 
venting the ripening of seed, the life of many annual 
plants may be preserved and the plants changed to bi- 
ennials or perennials. In such cases death, although the 
result of the constitution of the plant, may be postponed. 

We may ask then if the natural death of higher plants, 
usually attributed to exhaustion, cannot be explained more 
simply as the result of poisons produced in their meta- 
bolism. Many plants produce poisons which are fatal to 
animals and man. May they not also produce substances 
fatal to themselves? There is nothing improbable in the 
supposition that some of the poisons may develop when 
the seeds are ripening. By preventing the latter process, 
the ripening of the whole organism may also be prevented. 
Such a theory would explain the many cases of natural 
death which occur whilst the cell is far from having reached 
exhaustion. The equally numerous cases of partial death, 
such as that of flowers, whilst the same stem is still pro- 
ducing other flowers (e.g. geraniums) would be explained 
by a local action of the poisons not strong enough to kill 
the whole plant. 

I must insist that this theory, that natural death of the 
higher plants, is the result of auto-intoxication, is a mere 
hypothesis which future investigations may disprove. If, 
however, it comes to be confirmed, it would explain the 
coincidence of death and fructification more simply than 
the hypothesis of predestination. 

The higher plants may be subjects of auto-intoxica- 
tion in the same fashion as bacteria and yeasts. If these 
poisons were produced before the ripening of the seeds, 


the plants would remain sterile, leaving no descendants, 
so that the race would become extinct. The production of 
poisons at the time of fructification would not interfere 
with the succession of generations, and the race would be 
preserved. As the poisoning is not necessary, it is easy 
to understand why many plants survive seeding and escape 
natural death. The Dragon-tree, baobab, and the cedars, 
which I spoke of earlier, would be examples of such escape. 

Although the existence of auto-intoxication in the higher 
plants is still only a hypothesis, the natural death of bac- 
teria and yeasts by poisons which they themselves produce 
is an ascertained fact. 

In the plant world, therefore, there are examples of 
natural death (bacteria and yeasts) due to auto-intoxica- 
tion, and there are other cases where high or low plants 
escape natural death. 



Different origins of natural death in animals Examples of 
natural death associated with violent acts Examples of 
natural death in animals without digestive organs Natural 
death in the two sexes Hypothesis as to the cause of natural 
death in animals 

THE cases of natural death amongst animals differ from 
those found in the vegetable world by their greater variety 
and complexity. As M. Massart has shown for plants, 
so also natural death must have become established inde- 
pendently in different groups of animals. In some cases, 
the characters presented are strange and almost para- 

It is usual to contrast natural death with violent death 
on account of the difference between the two. None the 
less, natural death may occur in the animal kingdom, that 
is to say death resulting directly from the constitution, 
and yet in intimate association with violent acts. I will 
give some examples. 

Small, helmet-shaped organisms, transparent and grace- 
ful, are common on the surface of the sea. These have 
been described by zoologists under the name Pilidium. 
The organisation is simple. The body wall is a delicate 
pellicle, through which, on the lower surface, a mouth 
leads into a capacious stomach. Continual movements of 


waving cilia direct small particles of food through the 
mouth to the digestive stomach. As there are no organs 
of reproduction, it was assumed that these creatures were 
not adults, but floating larvae of some marine animal, 
and, after a good deal of trouble, it was found that the 
Pilidia were the young stages of ribbon-shaped worms of 
the group of Nemertines. At a definite stage in the life- 
history, a foetus begins to develop round about the stomach 
of the Pilfdium, and eventually completely encloses it and 
detaches it by violent muscular contractions. The end of 
the story is that the foetus abandons the body of the 
Pilidium carrying off with it the stomach, an organ neces- 
sary to the maintenance of life. The remnant of the Pili- 
dium swims about in the sea-water, but soon dies as the 
result of the mortal wound caused by the removal of the 
digestive organs. 

The act by which the Nemertine separates from its 
mother is violent, and yet the death of the Pilidium 
must be regarded as natural. It is the result of agencies 
within the body and not, as in most cases of accidental 
death, of violence from without. 

The group of Nematode worms contains many common 
intestinal parasites of man, such as Ascaris, Trichina, 
Trichocephalus, Oxyuris, &c., but also others that live 
free in soil or water or in such fluids as vinegar. They 
are protected by a strong cuticle, and some of them are 
viviparous, that is to say, instead of laying eggs they give 
birth to young worms already well grown and capable of 
independent activity. Amongst the human Nematode 
parasites, the Trichinae give birth to swarms of small larvae 
which easily escape from the body of the mother by the 
female generative aperture. In the case of some free-living 
Nematodes, however, the female aperture is too small to 


give passage to the rather stout larvae. More than forty 
years ago, when I was investigating the life-history 1 of 
one of these Nematodes (Diplogaster tridentatus) I was 
struck by the fact that the larvae could leave the body of 
the mother only by violence and after they had devoured 
most of its substance. These larvae develop from eggs 
produced within the maternal body. As the external re- 
productive aperture of the female is minute, the larvae 
cannot escape through it, but wander amongst the tissues 
tearing and absorbing them. The mother soon dies, and 
although her death is violent, it must be included in the 
category of natural death. 

From the ideological point of view it might be said 
that Pilidium and Diplogaster cease to live because they 
have fulfilled their function of giving rise to a Nemertine 
or young Nematodes. Their natural death would thus 
be predestined. There is no ground for such an interpre- 
tation. On the other hand, it is certain that this death, 
coming after the birth of the new generation, is in no way 
against the preservation of the species in which the extra- 
ordinary natural death by violence occurs. If the female 
orifice of Diplogaster were slightly larger, the larvae would 
emerge without difficulty and without causing the death of 
the mother which none the less would have fulfilled 
her purpose. 

All the cases of natural death amongst animals are not 
so brutal as those of the Pilidium and the Nemertine worms. 
In many instances the death is peaceful. As very fre- 
quently it is difficult to establish definitely that the death is 
natural, I shall select clear cases. 

Animals are occasionally found which are devoid of some 
organ necessary for prolonged life. The absence of a 

1 Archil', fiir Anatomic und Physiologic, 1864. 


digestive tract in an animal that lives in an environment 
rich in dissolved nutritive material (as for instance tape- 
worms living in the intestinal tract) is not surprising. 
But when creatures of the sea 6r of fresh water have no 
digestive tract, their life can be maintained only at the 
expense of nutritive material stored within them during 
embryonic life. The death which conies eventually is truly 
natural. The best cases, that is to say those which can 
be studied most completely, of such natural death occur 
amongst the Rotifera. These are minute creatures of fresh 
or sea water, at one time confused with the Infusoria, 
but possessed of a much more complex organisation. They 
have a well-developed digestive tube, organs of excretion, 
nervous system, and organs of sense. The animals are di- 
oecious ; in each species both males and females exist. 
Whilst the females have the complete structure of the 
species, the males are much reduced, and are devoid of 
a digestive canal. The cuticle is fairly stout, and they 
are unable to absorb dissolved nutriment through it; as 
they have no organs of digestion, their life must be 

To study in detail the life and death of these creatures, I 
selected a species sent to me by M. Haffkine. So far as 
I can judge, the species in question is a hitherto unknown 
member of the genus Pleurotrocha, and I propose for it 
the name Pleurotrocha haffkini. This rotifer is convenient 
to study as it thrives in vessels containing fresh-water to 
which some bread-crumb has been added (in the propor- 
tion of a gram of bread to 500 grams of water). 

The sexes of the little rotifer can be distinguished from 
the earliest age, for eggs that are to become females are 
much larger than those from which males develop. It 
is easy to isolate the male eggs and to follow the life-history 


up to the moment of natural death. The whole course of 
life from the laying of the egg until death lasts only about 
three days, and is probably the shortest duration of life 
in the animal kingdom. Although some Ephemeridae live 
only a few hours in the adult state, their total life-cycle 
is much longer than that of the rotifers, as the larval stages 
last for months or even for years. 

The little males (Fig. 16) begin to swim soon after 
hatching, the wheel-apparatus and the musculature being 
vigorous. They seek out the females, as their reproduc- 
tive organs are mature almost at the moment of hatching. 
The transparent body, which is devoid of digestive ap- 

paratus, swarms with mobile spermatozoa. As soon as 
the male has seized a female, he discharges the contents 
of his body. It might be supposed that such an evacuation 
would cause a violent perturbation of the system leading 
to the death of the organism. There is no question of this 
however. The males are able to live for twenty-four hours 
after having accomplished their function, and the period 
represents a third of their total duration of life. More- 
over, I have isolated males from females without any pro- 
longation of their lives. In one experiment, I isolated 
two males and placed a third in company with two females. 
It was the third specimen that lived longest. 

The natural death of the males is foreshadowed by a 
weakening of the movements; although the muscles and 



cilia remain mobile, the whole animal moves only spas- 
modically; sometimes the muscles of the head contract, 
sometimes those of the tail, but no locomotion occurs. 
Occasionally there is a violent effort of ciliary motion as if 
the attempt were being made to overcome the immobility 
of the body. Such a condition lasts for several hours and 
is followed by death. The spermatozoa inside the body 
retain activity last of all. 

Towards the crisis, bacteria, which abound in the medium 
occupied by the rotifers, begin to attack the males. Some 
cluster round the head, others round the tail, although 
none of them can effect entrance to the body. The death 
of the males cannot be attributed to microbial infection, 
but comes from some intrinsic cause. 

Is it inanition that is the cause of death ? I do not 
think so, because up to the time of death the tissues appear 
to be unmodified. In the case of the females I have some- 
times seen phenomena of inanition. In old and exhausted 
cultures the starved females become thin, flattened and 
quite transparent, and the tissues lose their granular ap- 
pearance. No such changes are visible in the dying males, 
the tissues of which, on the contrary, retain a normal 

The most probable explanation is that death comes from 
poisoning by the secretions of the tissues themselves. The 
large size of the organs of excretion indicates that in the 
course of metabolism waste matter is produced some of 
which is got rid of. If, after a time, the secretions are 
insufficiently eliminated, the tissues must be poisoned. As 
death is preceded by a spasm of uncoordinated movement, 
it appears as if the fatal intoxication of the males affected 
the nervous system first. The vibrating cilia and the 
muscles are attacked later. 

There can be no doubt but that the death of these male 


rotifers is natural in the fullest sense. The females, how- 
ever, although they are provided with complete digestive 
organs, do not escape a similar fate. Their life is longer 
and more complex than that of the males, and so is subject 
to many more chances. The females therefore may come 
to die from starvation or from other external, accidental 
causes. But, if they are kept in favourable conditions, 
they may live for about fifteen days, towards the end of 
which they die naturally, exhibiting the symptoms that I 
have described in the case of the males (Fig. 17). 

Rotifers are not the only animals which undergo natural 
death in a fashion quite unlike the violent end of Pilidium 

FIG. 17. Female Pleurotrocha haffkini, which has died a natural death. 

and Diplogaster. There are other cases amongst inverte- 
brates, but I shall limit myself to describing one that is 
well ascertained. 

More than fifty years ago, Dana, the American 
naturalist, discovered a pelagic marine creature with char- 
acters so curious that he gave to it the name Monstrilla. 
It is a little crustacean akin to the Cyclops of lakes. But 
although the latter is endowed with the organs necessary 
to capture and digest food, Monstrilla has neither organs 
of prehension nor a digestive canal. It is a highly muscu- 
lar animal with organs of sense and reproduction and a 
nervous system ; but it is devoid of apparatus for prolong- 



ing life by nutrition. 
Monstrilla therefore is a 
creature doomed to 
natural death. 

The detailed observa- 
tions of M. Malaquin 1 
have supplied full infor- 
mation regarding this 
strange life-history. Mon- 
strilla passes a portion of 
.5 its life as a parasite on 
jf Annelid worms. In that 


stage it accumulates the 
necessary material for the 
growth of the sexual pro- 
ducts (ova and sperma- 
tozoa) and for free life in 
the sea whilst the young 
are developing. It is not 
only the males which 
have no digestive appara- 
tus. The females also 
lack it, which is the more 
surprising as they carry 
about the eggs attached 
to the body (as is done by 
many other Crustacea, 
such as crayfish and lob- 
sters) until the young are 
ready to hatch (Fig. 18). 
M. Malaquin thinks that 
Monstrillas die of starvation. 
1 Archives de Zoologie exptrimentale, 1901, vol. ix, p. 81. 


" As they are without a digestive tube or organs of 
prehension or mastication," M. Malaquin says (p. 192), 
" the Monstrillas, which have no means of nutrition, are 
doomed to death from inanition after a short pelagic life. 
This is a logical inference from their structure." 

In support of his view, M. Malaquin states that before 
death the tissues and organs show plain signs of degenera- 

" The eyes first show traces of degeneration. The pig- 
ment spreads and disappears little by little and then the 
visual elements fade out." 

" Finally, individuals, usually females, show complete 
degeneration. A female taken in a fine-meshed net showed 
no trace of organs in the head; the eyes, the brain and 
the intestinal tract had disappeared almost completely. 
The antennae were reduced to stumps consisting of the 
lowest joint and a portion of the second. These were clear 
indications of the senility that precedes death " (p. 194). 

Such evidence not only supports the hypothesis that 
the natural death of Monstrilla is due to inanition, but 
is opposed to a similar interpretation being applied to the 
case of male rotifers, in which death is not preceded by 
wasting of the organs. The death of some insects, which 
comes rapidly after the adult stage has been reached, cannot 
readily be attributed to starvation. In the strange butter- 
flies known as psychids (Solcnobid) some of the females 
lay eggs without having been fertilised, 1 and their life in 
the adult condition lasts only a day. On the other hand, 
other females of the same butterfly are fertilised before 
laying their eggs and in this case survive for more than 
a week although they take no food. The rapid death of 
the first-mentioned set cannot be attributed to inanition. 
1 Observations of Dr. Speyer, quoted by Weismann. 


In some Ephemeridce, which supply good cases of 
natural death, the end comes after a few hours of adult 
life without any sign of degeneration of the organs. As 
in others (Chloe), life lasts for several days without food 
having been taken, it is clear that inanition is not the 
cause of the swift arrival of death in the first set. It is 
much more probable that the natural death is due to an 
auto-intoxication which takes effect at different intervals 
of time in different circumstances. 1 

In the higher animals such as vertebrates the conditions 
are less favourable than in the case of insects for the in- 
vestigation of the causes of natural death. Vertebrates 
have always well-developed organs of digestion and so 
live a relatively longer time and encounter a greater number 
of chances of accident, with the result that in most cases 
death comes from external accidental causes. Vertebrates 
usually perish from hunger or cold, or are devoured by 
their enemies or killed by the attacks of parasites or dis- 
eases. There remains only the human race amongst the 
more highly developed animals, in which to study the 
onset of natural death. And in the human race cases 
which may be designated as natural are extremely rare. 
1 See The Nature of Man. 



Natural death in the aged Analogy of natural death and 
sleep Theories of sleep Ponogenes The instinct of sleep 
The instinct of natural death Replies to critics Agree- 
able sensation at the approach of death 

THE death of old people, which has often been described as 
natural death, is in most cases due to infectious diseases, 
particularly pneumonia (which is extremely dangerous) or 
to attacks of apoplexy. True natural death must be very 
rare in the human race. Demange l has described it as 
follows : " Arrived at extreme old age, and still preserv- 
ing the last flickers of an expiring intelligence, the old man 
feels weakness gaining on him from day to day. His 
limbs refuse to obey his will, the skin becomes insensitive, 
dry, and cold ; the extremities lose their warmth ; the face 
is thin ; the eyes hollow and the sight weak ; speech dies 
out on his lips which remain open ; life quits the old man 
from the circumference towards the centre ; breathing grows 
laboured, and at last the heart stops beating. The old 
man passes away quietly, seeming to fall asleep for the 
last time." Such is the course of what properly speaking 
is natural death. 

The natural death of human beings cannot be regarded 
as due to exhaustion from reproduction or from inanition, 

1 tude clinique sur la vieillesse, Paris, 1886, p. 145. 


as in the case of Monstrilla. It is much more likely that it 
is due to an auto-intoxication of the organism. The close 
analogy between natural death and sleep supports this 
view, as it is very probable that sleep is due to poisoning 
by the products of organic activity. 

It is more than fifty years since sleep was explained as the 
result of auto-intoxication. Obersteiner, Binz, Preyer, and 
Errera are among the competent men of science who have 
taken this view. The first two attributed sleep to an 
accumulation in the brain of the products of exhaustion 
which are carried away by the blood during repose. The 
attempt has been made even to discover the nature of these 
narcotic substances. Some investigators think that an 
acid, produced during the activity of the organs, is stored 
up in quantities that cannot be tolerated. During sleep, 
the organism gets rid of this excess of acid. 

Preyer 1 tried to put the problem upon a more exact 
basis by the theory that the activity of all the organs gives 
rise to substances which he called ponogenes and which 
he regarded as producing the sensation of fatigue. 
According to him these substances accumulate during the 
waking hours, and are destroyed by oxidation during 
sleep. Preyer thinks that lactic acid is the most important 
of the ponogenes, and lays stress on its narcotic effect. If 
his theory were correct, there would be a remarkable 
analogy between the auto-intoxication by lactic acid in the 
cases of man and animals, and the case of bacteria which 
produce the same acid and the fermenting activity of which 
is arrested as the acid accumulates. Just as sleep may be 
transformed to natural death, so also the arrest of lactic 
fermentation may be followed by the death of the bacteria 
which form the acid. 

1 Revue scientifique, 1877, p. 1173. 


So far, however, there has been no confirmation of 
Preyer's theory. Errera 1 has brought forward against it 
another theory according to which the cause of sleep is 
not acid products, but certain alkaline substances described 
by M. Armand Gautier under the name of leucomaines. 
Gautier laid down that these substances act on the nervous 
centres and produce fatigue and sleepiness. According to 
Errera they might very well be the cause of sleep, as that 
comes on at a time when there is the greatest accumulation 
of these leucomaines in the body. He thinks that their 
action in producing sleep is a direct intoxication of the 
nerve centres. During sleep they are removed, and the 
disturbance which was produced in the organism is arrested. 

If it were possible to accept Errera's theory, a kind of 
analogy could be established between sleep and natural 
death on the one hand, and the arrest of development and 
death of yeast grown in nitrogenous media on the other 
hand, because in the latter case the poisoning is produced 
by an alkaline salt of ammonia. It must be confessed, 
however, that the actual state of our knowledge does not 
allow of a definite view of the real mechanism of the sleep- 
producing intoxication. Our ideas regarding leucomaines 
in general are still incomplete, and, recently, one of them, 
adrenaline, the product of the supra-renal capsules, has been 
investigated. Adrenaline is an alkaloid 2 which is pro- 
duced in the supra-renal bodies and is discharged into the 
blood. It has the power of contracting arteries strongly, 
and has been used to control blood-pressure. When it is 
given in large quantities or in frequent doses, it acts as a 
true poison, whilst, in small doses, it produces anaemia of 
the organs and has a special influence on the nervous 

1 Revue scientifique, 1887, 2nd part, p. 105. 

8 Gabriel Bertrand, Annales de tlnstitut Pasteur, 1904. p. 672. 


centres. Dr. Zeigan 1 has shown that a milligramme of 
adrenaline, mixed \vith five grammes of normal salt solu- 
tion injected into the brain of cats, produces a soporific 
action. " About a minute after the injection, the animal 
appears to be plunged into deep sleep which lasts from 30 to 
50 minutes. During this time, the sensitiveness of the animal 
has completely ceased throughout the body, and for some 
time after that it is much decreased. When they awake 
the animals seem to have been drunk with sleep for some 
time." Sleep is generally associated with anaemia of the 
brain, and as adrenaline can actually produce such anaemia, 
it might be supposed that this narcotic substance is the 
most important of the organic products which give rise 
to sleep. Against this hypothesis, however, some weight 
must be given to recent investigations on fatigue and its 

Each stage in the advance of knowledge has had its 
influence, on the study of the interesting and complex 
problem of sleep. When it was thought that alkaloids 
(ptomaines) were of great importance in infectious diseases, 
it was attempted to explain sleep as due to the action of 
similar bodies. Now, when we believe that in such diseases 
the chief part is played by poisons of extremely complex 
chemical composition, the attempt is made to explain 
fatigue and sleep by similar bodies. 

Weichardt 2 has recently made the best known investiga- 
tions in this direction. This young man maintains with 
ardour the view- that during the activity of organs there is 
an accumulation of special materials which are neither 
organic acids nor leucomaines, but which are much more 
like the toxic products of pathogenic bacteria. 

1 Therapeutische Monatshefte, 1904, p. 193. 

2 Miinchener medicinische Wochenschrift, 1904, No. i ; Verhandlungen 
der physiologischen Gesellschaft zu Berlin, Dec. 5th, 1904, 


Weichardt made animals in his laboratory go through 
fatiguing movements for hours and then killed them. The 
extract from muscles of such animals had a powerful toxic 
effect when it was injected into normal animals, producing 
lassitude and sometimes death within 20 to 40 hours. As 
all attempts to determine the exact chemical nature of this 
fatigue-producing substance were baffled, it is impossible 
to get an exact account of it. Amongst its properties there 
is one of great interest. When it has passed into the cir- 
culation of normal animals in quantities insufficient to 
produce death, it excites the formation of an anti-toxin 
in the same way as a poison of diphtheria stimulates the 
production of a diphtheria anti-toxin. 

When Weichardt injected into animals a mixture of the 
poison which produces fatigue with small doses of the 
serum antidote, no results followed. The neutralising effect 
of the antidote was apparent even when it was introduced 
by the mouth. Towards the end of his investigations. 
Weichardt supposed that it would be possible to obtain a 
material that would prevent fatigue. 

Although it is still impossible to specify exactly the 
nature of the substances which accumulate during the 
activity of organs and which produce fatigue and sleep, 
it is becoming more and more probable that such sub- 
stances exist, and that sleep is really an auto-intoxication 
of the organism. So far, such a theory has not been shaken 
by any argument. Recently M. E. Claparede, 1 a psycho- 
logist of Geneva, has argued against the current theory 
of sleep. He thinks that it is contradicted by the fact that 
new-born infants sleep a great deal, whilst very old people 
sleep very little. This fact, however, can readily be ex- 

1 Archives des sciences physiques et naturelles, Geneva, March, 1905, 
vol. xvii ; Archives de physiologic, vol. iv, p. 245. 


plained by the greater sensibility of the nerve centres of 
infants, as shown with regard to many harmful agencies. 
The other objections of Claparede, such as the fact that 
sleepiness is induced by exercise in the open air, or that 
excess of sleep itself produces sleepiness, are not really 
incompatible with the theory of auto-intoxication. They 
are facts of secondary importance probably depending on 
some complication which the present state of our know- 
ledge makes it difficult to indicate exactly. The insomnia 
of neurasthenia, which Claparede brings forward as another 
objection, can readily be explained as due to hyperaesthesia 
of the nervous tissues which lose part of their sensitive- 
ness to poisons. 

On the other hand, there are many well established facts 
in agreement with the theory of auto-intoxication. Leav- 
ing out of the question sleep induced by narcotics, I may 
mention in this connection the so-called "sleeping sick- 
ness." It has been proved that this disease is caused by 
a microscopic parasite, the Trypanosoma gambiense of 
Dutton, which develops in the blood and spreads to the 
liquid of the membranes surrounding the central nervous 
system. One of the most typical symptoms of the advanced 
stages of this disease is continual drowsiness. " The 
drowsiness increases progressively, and the habitual atti- 
tude becomes characteristic ; the head is bent on the breast ; 
the eyelids are closed; in earlier stages the invalid can be 
aroused easily, but, after a time, incurable attacks of sleep 
overcome the patient in all circumstances, but especially 
after meals. These fits of sleepiness become longer and 
deeper, until they reach a comatose condition from which 
it is almost impossible to arouse the patient." 1 The total 

1 Laveran and Mesnil, Trypanosomes et Trypanosomiases, Paris, 1904, 
p. 328. 


result of medical knowledge of this disease is that it is 
impossible to doubt that the sleepiness is due to intoxica- 
tion produced by the poison of the trypanosome. 

Claparede has opposed what he calls an " instinctive" 
theory to the toxic theory of sleep. According to this 
theory, sleep is the manifestation of an instinct " the object 
of which is to arrest activity ; we do not sleep because we 
are intoxicated or exhausted, but to prevent ourselves from 
falling into such a condition." However, in order to bring 
this narcotic instinct into play, certain conditions are neces- 
sary, one of which certainly would be the intoxication of 
the nerve centres. M. Claparede supposes that sleep is an 
active phenomenon, induced when waste matter begins to 
accumulate in the organism. " To bring about sleep, the 
nerve centres must be influenced by waste matter, and 
this influence can readily be regarded as a kind of intoxica- 

Hunger is an i.nstinctive sensation as much as sleepiness, 
but it does not appear until our tissues are in a condition 
of exhaustion, the exact nature of which cannot as yet be 
indicated. There is no real contradiction between the toxic 
and instinctive theories of sleep. The two theories repre- 
sent different sides of a special condition of the organism. 

The analogy between sleep and natural death is in favour 
of the supposition that the latter, also, is due to an intoxica- 
tion much more profound and serious than that which 
results in sleep. Therefore, as natural death in human 
beings has been studied only very superficially, it is impos- 
sible to do more than frame theories regarding it. 

It would be natural if, just as in sleep there is an instinc- 
tive desire for rest, so also the natural death of man were 
preceded by an instinctive wish for it. As I have already 
discussed this subject in the " Nature of Man " (chap, xi) 


I need not deal with it at length here. I should like, how- 
ever, to add some information which I have recently 

The most striking fact in favour of the existence of the 
instinct for natural death in man appears to me to have 
been related by Tokarsky in regard to an old woman. 
While Tokarsky was alive I asked one of his friends to 
obtain for me further details of this very interesting case. 
Unfortunately Tokarsky could add nothing to what he had 
already published in his article. I think that I have dis- 
covered the source of his information. In his famous book 
on the Physiology of Taste 1 Brillat-Savarin relates as fol- 
lows: "A great-aunt of mine died at the age of 93. 
Although she had been confined 'to bed for some time her 
faculties were still well preserved, and the only evidence 
of her condition was the decrease in appetite and weaken- 
ing of her voice. She had always been very friendly to 
me, and once when I was at her bedside, ready to tend 
her affectionately, although that did not hinder me from 
seeing her with the philosophical eye that I always turned 
on everything about me, 'Is it you, my nephew?' she 
said in her feeble voice. ' Yes, Aunt, I am here at your 
service, and I think you will do very well to take a drop 
of this good old wine.' ' Give it me, my dear ; I can always 
take a little wine.' I made ready at once, and gently 
supporting her, gave her half a glass of my best wine. 
She brightened up at once, and turning on me her eyes 
which used to be so beautiful, said : ' Thank you very 
much for this last kindness ; if you ever reach my age you 
will find that one wants to die just as one wants to sleep.' 
These were her last words, and in half an hour she fell into 
her last sleep." The details make it certain that this was' 
1 Paris, 1834, 4th edition, vol. ii, p. 118. 


a case of the instinct of natural death. The instinct showed 
itself at an age not very great in the case of a woman who 
had preserved her mental faculties. Generally, however, it 
seems not to appear till much later, for old men usually 
exhibit a keen wish to live. 

It is a well-known saying that the longer a man has lived 
the more he wishes to live. Charles Renouvier, 1 a French 
philosopher who died a few years ago, has left a definite 
proof of the truth of the saying. When he was eighty- 
eight years old, arid knew that he was dying, he recorded his 
impressions in his last days. Let me quote from what he 
wrote four days before his death. " I have no illusions about 
my condition ; I know quite well that I am going to die, per- 
haps in a week, perhaps in a fortn-ight. And I have still 
so much to say on my subject." "At my age I have no 
longer the right to hope : my days are numbered, and 
perhaps my hours. 1 must resign myself." " I do not die 
without regrets. I regret that I cannot foresee in any way 
the fate of my views." " And I am leaving the world 
before I have said my last word. A man always dies 
before he has finished his work, and that is the saddest of 
the sorrows of life." " But that is not the whole trouble, 
when a man is old, very old, and accustomed to life, it is 
very difficult to die. I think that young men accept the 
idea of dying more easily, perhaps more willingly than 
old men. When one is more than eighty years old, one is 
cowardly and shrinks from death. And when one knows 
and can no longer doubt that death is coming near, deep 
bitterness falls on the soul." " I have faced the question 
from all sides in the last few days; I turn the one idea over 
in my mind; I know that I am going to die, but I cannot 
persuade myself that I am going to die. It is not the 
1 Revue de metaphysique et de morale, March, 1904. 


philosopher in me that protests. The philosopher does not 
fear death ; it is the old man. The old man has not the 
courage to submit, and yet I have to submit to the in- 

I know a lady, a hundred and two years old, who is so 
oppressed by the idea of death, that those about her have to 
conceal from her the death of any of her acquaintances. 
Mde. Robineau, however, when between one hundred and 
four and one hundred and five years old, became quite in- 
different to the close approach of her own 'death. She often 
expressed a wish for it, thinking herself useless in the 

M. Yves Delage 1 in an analysis of my "Nature of 
Man " doubted the existence of an instinct for death. 
" Animals," said he, " cannot have the instinct for death, 
because they do not know of death. In their case, we must 
consider that what happens is an apathy tending to the 
abolition of the sense of self-preservation. In man, the 
knowledge of death implies that the indifference to its 
approach cannot be an instinct." "There may be de- 
veloped, at the end of life, a special state of mind which 
accepts death with indifference or with pleasure, but such 
a state cannot be designated as an instinct." M. Delage, 
however, does not suggest what the state of mind in ques- 
tion is to be called. As the aunt of Brillat-Savarin com- 
pared her sensations just before death with the desire to 
sleep, and as this desire is an instinctive manifestation, I 
think that the cheerful acquiescence in death, exhibited by 
extremely old people, is also a kind of instinct. However, 
the important matter is that the sentiment exists, and not 
what we are to call it. M. Delage is far from denying its 

1 Annfo biologique, vol. vii, p. 595. 


Dr. Cancalon, 1 another of my critics, cannot admit the 
existence of an instinct of death, "because of the theory 
of evolution. Of what good would it have been, as M. 
Metchnikoff tells us that natural death is very rare; how 
could it have been transmitted, as it comes into existence 
long after the age of reproduction, and how could it have 
aided the survival of the species? If its existence were 
proved as the result of biological evolution, it would be a 
contradiction of adaptation and an argument in favour of 
final causes." I .cannot agree in any way with these 
opinions. In the first place, it is well known that men and 
animals have many harmful instincts that do not tend to 
the survival of the species. I need recall only the dis- 
harmonic instincts which I described in the " Nature of 
Man," such as the anomalies of the sexual instinct, the 
instinct which drives parents to devour their young or 
which attracts insects to flames. The instinct of natural 
death is far from being harmful, and may even have many 
advantages. If men were convinced that the end of life 
were natural death accompanied by a special instinct like 
that of the need for sleep, one of the greatest sources of 
pessimism would disappear. Now pessimism is the cause 
of the voluntary death of a certain number of people and of 
many others refraining from reproduction. The instinct 
of natural death would contribute to' the maintenance of 
the life of the individual and of the species. On the other 
hand, there is no difficulty in admitting the existence of 
instincts hostile to the preservation of the species, espe- 
cially in the case of man, in whom individualism has 
reached its highest development. As man is the only 
animal with a definite notion of death, there is nothing 
extraordinary if it is in man that the instinctive wish for 
1 Revue occidentals, July ist, 1904, vol. xxx, p. 87. 


death develops. M. Cancalon denies the possibility that 
death can be pleasant, as it is the arrest of the physio- 
logical functions ; but as sleep and syncope are often pre- 
ceded by very pleasant sensations, why may not this also 
happen in natural death ? Several facts prove it beyond 
dispute. It is even probable that the approach of natural 
death is one of the most pleasant sensations that can exist. 

It is indubitable that in a large number of cases of death, 
the cessation of life is associated with very painful sensa- 
tions. One has only to see the horror shown in the faces 
of. many dying people to be convinced of this, but there 
are diseases and serious accidents in which the approach 
of death does not arouse sorrowful sensations. I myself, 
in a crisis of intermittent fever, in which the temperature 
descended in a very short time from about 106 Fahr. to 
below normal, experienced a feeling of extraordinary 
weakness, certainly like that at the approach of death. This 
sensation was much more pleasant than painful. In two 
cases of serious morphia poisoning, my sensations were 
more agreeable ; I felt a pleasant weakness, associated with 
a sensation of lightness of the body, as if I were floating 
in the air. 

Those who have noted tjie sensations of persons rescued 
from death have related similar facts. Prof. Heim, of 
Zurich, has described a fall in the mountains which nearly 
killed him, as well as several similar accidents to Alpine 
tourists. In all these cases he states that there was a sensa- 
tion of pleasure. 1 Dr. Sollier has told of a young woman 
addicted to morphia, who had been convinced that she was 
at the point of death. On recovering from a most serious 
attack of syncope, from which she was restored only by 
giving another dose of morphia, she cried: "I seem to 

1 Egger, " Le mot des mourants" Revue philosophique, 1896, i, p. 27. 


come from far away; how happy I was! " Another of 
Dr. Sollier's patients, a lady who had an attack of peri- 
tonitis from which she expected to die, felt herself "suf- 
fused with a feeling of well-being, or rather the absence of 
all pain." In a third case of Dr. Sollier, a young woman 
suffering from puerperal fever, feeling herself at the point 
of death, had a similar sensation "of physical well-being 
and of detachment from everything." 1 

As a sensation of happiness occurs even in cases of patho- 
logical death, it is much more likely to occur in natural 
death. If natural death be preceded by the loss of the 
instinct of life and by the acquisition of a new instinct, it 
would be the best possible end compatible with the real 
organisation of human nature. 

I do not pretend to give the reader a finished study on 
natural death. This chapter of Thanatology, the science 
of death, only opens the subject; but it is already ap- 
parent that study of the circumstances of natural death in 
plants, in the animal world, and in human beings, may 
give facts of the highest interest to science and humanity.- 

1 Ibid.) pp. 303-307 ; v. also Bulletin de PInstitut gtntral phycholog., 
1903, p. 29. 




Complaints of the shortness of our life Theory of " medi- 
cal selection " as a cause of degeneration of the race 
Utility of prolonging human life 

ALTHOUGH the duration of the life of man is one of the 
longest amongst mammals, men find it too short. From 
the remotest times the shortness of life has been complained 
of, and there have been many attempts to prolong it. Man 
has not been satisfied with a duration of life notably greater 
than that of his nearest relatives, and has wished to live 
at least as long as reptiles. 

In antiquity, Hippocrates and Aristotle thought that 
human life was too short, and Theophrastus, although he 
died at an advanced age (he lived probably seventy-five 
years) lamented when he was dying " that nature had given 
to deer and to crows a life so long and so useless, and to 
man only one that was often very short." 1 

Seneca (Debrevitatevitce) and later, in the i8th century, 
Haller, strove in vain against such complaints, which have 
lasted until our own days. Whilst animals have no more 

1 Cicero, Tusculanes, chap, xxviii. 


than an instinctive fear of danger, and cling to life without 
knowing what death is, men have acquired an exact idea of 
death, and their knowledge increases their desire to live. 

Ought we to listen to the cry of humanity that life is too 
short and that it would be well to prolong it ? Would it 
really be for the good of the human race to extend the dura- 
tion of the life of man beyond its present limits ? Already 
it is complained that the burden of supporting old people is 
too heavy, and statesmen are perturbed by the enormous 
expense which will be entailed by State support of the 
aged. In France, in a population of about 38 millions, 
there are two millions (1,912, 153) who have reached the age 
of 70, that is to say, about five per cent, of the total. The 
support of these old people absorbs a sum of nearly 
^6,000,000 per annum. 1 However generous may be the 
views of the members of the French Parliament, many of 
them hesitate at the idea of so great a burden. Without 
doubt, men say, the cost of maintaining the aged will be- 
come still heavier if the duration of life is to be prolonged. 
If old people are to live longer, the resources of the young 
will be reduced. 

If the question were merely one of prolonging the life of 
old people without modifying old age itself, such considera- 
tions would be justified. It must be understood, however, 
that the prolongation of life would be associated with the 
preservation of intelligence and of the power to work. In 
the earlier parts of this book I have given many examples 
which show the possibility of useful work being done by 
persons of advanced years. When we have reduced or 
abolished such causes of precocious senility as intemperance 
and disease, it will no longer be necessary to give pensions 

1 Rapport de M. Bienvenu-Martin k la Chambre des deputes, Paris, 


at the age of sixty or seventy years. The cost of supporting 
the old, instead of increasing, will diminish progressively. 

If attainment of the normal duration of life, which is 
much greater than the average life to-day, were to over- 
populate the earth, a very remote possibility, this could be 
remedied by lowering the birth-rate. Even at the present 
time, while the earth is far from being too quickly peopled, 
artificial limitation of the birth-rate takes place perhaps to 
an unnecessary extent. 

It has long been a charge against medicine and hygiene 
that they tend to weaken the human race. By scientific 
means unhealthy people, or those with inherited blemishes, 
have been preserved so that they can give birth to weak 
offspring. If natural selection were allowed free play, such 
individuals would perish and make room for others, stronger 
and better able to live. Haeckel has given the name 
" medical selection " to this process under which humanity 
degenerates because of the influence of medical science. 

It is clear that a valuable existence of great service 
to humanity is compatible with a feeble constitution and 
precarious health. Amongst tuberculous people, those 
with inherited or acquired syphilis, and those with a con- 
stitution unbalanced in other ways, that is to say, amongst 
so-called degenerates, there have been individuals who have 
had a large share in the advance of the human race. I need 
only instance the names of Fresnel, Leopardi, Weber, 
Schumann and Chopin. It does not follow that we ought 
to cherish diseases and leave to natural selection the duty of 
preserving the individuals which can resist them. On the 
other hand, it is indispensable to try to blot out the diseases 
themselves, and, in particular, the evils of old age, by the 
methods of hygiene and therapeutics. The theory of medi- 
cal selection must be given up as contrary to the good of the 


human race. We must use all our endeavours to allow men 
to complete their normal course of life, and to make it pos- 
sible for old men to play their parts as advisers and judges, 
endowed with their long experience of life. 

To the question propounded at the beginning of this sec- 
tion of my book, I can make only one answer : Yes, it is 
useful to prolong human life. 



Ancient methods of prolonging human life Gerokomy 
The " immortality draught " of the Taoists Brown- 
Se"quard's method The spermine of Poehl Dr. Weber's 
precepts Increased duration of life in historical times 
Hygienic maxims Decrease in cutaneous cancer 

MEN of all times have attempted all manner of devices to 
bring about an increase of years, although they have not 
considered the problem in its general bearing. 

In Biblical times it was believed that contact with young 
girls would rejuvenate and prolong the life of feeble old 
men. In the first Book of Kings it is related as follows : 

" Now King David was old and stricken in years; and 
they covered him with clothes, but he gat no heat. 

"Wherefore his servants said unto him, Let there be 
sought for my Lord the king a young virgin ; let her stand 
before the king and let her cherish him, and let her lie in 
thy bosom, that my lord the king may get heat " (Kings I., 
chap. i.). 

This device, afterwards called gerokomy, was employed 
by the Greeks and Romans, and has had followers in 
modern times. Boerhave, the famous Dutch physician 
(1668 1738), "recommended an old burgomaster of 
Amsterdam to lie between two young girls, assuring him 
that he would thus recover strength and spirits." After 
quoting this, Hufeland, the well-known author of " Macro- 


biotique " in the eighteenth century, made the following 
reflection : " If it be remembered how the exhalations 
from newly opened animals stimulate paralysed limbs, and 
how the application of living animals soothes a violent pain, 
we cannot refuse our approval to the method." 1 

Cohausen, a doctor of the eighteenth century, published a 
treatise on a Roman, Hermippus, who had died aged a 
hundred and fifteen years. He had been a master in a 
school for young girls, and his life, passed in their midst, 
was greatly prolonged. " Accordingly," commented 
Hufeland (p. 6), " he gives the excellent advice to breathe 
the air of young girls night and morning, and gives his 
assurance that by so doing the vital forces will be 
strengthened and preserved, as adepts know well that the 
breath of young girls contains the vital principle in all its 

In the Eastern half of the world equal ingenuity was exer- 
cised in the attempt to rejuvenate the body and renew the 
forces of man. The successors of Lao-Ts searched for a 
beverage that would confer immortality and have recounted 
extraordinary matters concerning it. 

The Emperor of China, Chi-Hoang-Ti (221 209 B.C.), 
displayed extreme friendliness to the Taoists, believing that 
these had the secret of long life and immortality. In his 
reign, Su-Chi, a Taoist magician, persuaded him that east- 
wards of China there lay fortunate islands inhabited by 
genii whose pleasure it was to give their guests to drink of 
a beverage conferring immortality. Chi-Hoang-Ti was so 
delighted with the news that he equipped an expedition to 
discover the islands. 2 

1 L'Art de prolonger la vie humaine (French translation), Lausanne, 
1809, p. 5. 
1 A. ReVille, Histoire des religions, vol. iii, Paris, 1889,^428. 


Later on, in the dynasty of the Tchengs (618 907), when 
Taoism had again become a religion in favour at court, 
efforts were made to obtain imperial patronage for the 
draught of immortality, and magicians were in high favour. 
The Taoist writers called this drink Tan or Kin-Tan, the 
"golden elixir." According to Mayers, the chief ingredi- 
ents of this marvellous compound were " cinnabar, the red 
sulphate of mercury, and a red salt of arsenic, potassium 
and mother-of-pearl. The preparation of it required nine 
months, and it passed through nine changes. One who 
had drunk of it was changed to a crane, and in this form 
could ascend to the dwellings of the genii, there to abide 
with them." 1 

The Taoists represent their saints, in the shade of willows, 
seeking the elixir of life, and in Chinese Buddhist temples 
there are placed votive cakes shaped like the tortoise, a 
sacred animal and the symbol of long life. Worshippers 
let stones of divination fall on these cakes and so ascertained 
if their lives were to be prolonged, promising for each sub- 
sequent year as many cakes as the divinity might demand. 

The mysticism of the East reached Europe in the Middle 
Ages, and then, and even in modern times, drugs were used 
to prolong life. Cagliostro, the celebrated quack of the 
eighteenth century, boasted that he had discovered an elixir 
of life by the use of which he had survived for many 
thousand years. 

There still exists, in some modern pharmacopoeias, an 
" elixir ad longam vitam " compounded of aloes and other 
purgatives. Analogous preparations are known, such 
as the " vital essence of Augsburg " which is a mixture of 
purgatives and resins. 

Serious physicians have rejected such preparations of the 
1 A. R^ville, loc. cit., p. 455. 


quacks. They have abandoned the search for a specific, 
and, in their efforts to prolong human life, have relied on 
common rules of hygiene, such as cleanliness, exercise, 
fresh air, and general sobriety. In our own days, Brown- 
Sequard is an isolated instance of a seeker for a specific 
against senescence. This distinguished physiologist, set- 
ting out from the view that the weakness of old men is due 
partly to diminution of the secretions of the testes, hoped 
to find a remedy in the employment of subcutaneous injec- 
tions of emulsions of the testes of animals (dogs and guinea- 
pigs). Brown-S^quard, 1 then aged 72 years, gave himself 
several such injections, and declared that he found himself 
reinforced and rejuvenated. Since then, numbers of per- 
sons have undergone the treatment which for a time was in 
vogue. The observations of physicians, made on old men 
and sick persons, have not justified the hopes which were 
entertained of the mode of treatment. Furbringer, 2 in par- 
ticular, working in Germany, has discredited the injections 
of Brown-S^quard. However, instead of following exactly 
the original prescription, Furbringer employed a testicular 
emulsion which had been previously raised to the boiling- 
point. Brown-Se"quard's method has not resisted scientific 
investigation, and although it is still occasionally employed 
in France, it has been given up in many countries. 

Brown-Se'quard laid stress on the efficacy of emulsions of 
testis as opposed to chemical substances prepared from the 
gland. Other scientific men, on the other hand, have 
attached value to such substances and in particular to an 
organic alkali the salt of which is known as spermine. 
That salt, made by Poehl of St. Petersburg, has been 
largely used. Several observers declare that its employ- 

1 Comptes rendus de la Societt de Biologie, 1899, p. 415. 

2 Deutsche medicin. Wochenschrift^ 1891, p. 1027. 


ment, injected in solution or even absorbed directly as a 
powder, has been followed by a strengthening of bodily 
power enfeebled by age or labour. 

As I have no personal experience of spermine, I shall 
quote from Professor Poehl 1 some indications of its effi- 
cacy. Several physicians (Drs. Maximovitch, Bukojemsky, 
Krieger and Postoeff) have given injections of spermine 
to enfeebled old men who had lost appetite and sleep, and 
have noted improvement lasting for months. From the 
instances given, I have selected that of an old lady of 
ninety-five years, afflicted with severe sclerosis of the arte- 
ries, with no appetite, a bad digestion and constipation. 
This patient had complained for several years of sacral 
pains, and moreover was nearly quite deaf and suffered from 
periodic attacks of malarial fever. The injections of sper- 
mine, given for a period of fifteen months, restored the old 
lady to such an extent that she recovered her power of 
hearing and felt the sacral pains only slightly and after a 
long walk. Her general condition was highly satisfactory. 

Spermine, as it has been used medically, is prepared not 
only from the testes of animals but from the prostate gland, 
ovary, pancreas, thyroid gland and spleen. The substance 
is not specially associated with spermatozoa but has a wide 
distribution in the mammalian body. 

In the medical treatment of the evils of old age, testicular 
emulsions or spermine have not been so favoured as general 
hygienic measures. Dr. Weber, 2 a London medical man, 
has recently summarised more general measures, and his 
evidence is the more important as he has been able to test 

1 Die physiologisch-chemisch. Grundlagen d. Spermintheorie, Berlin, 

2 British Medical Journal, 1904 ; Deutsche Mediz. Wochenschr.^ 1904, 
Nos. 1 8-2 1. 


the efficacy of his precepts in his own case. Dr. Weber is 
83 years old, and in his practice has cared for many other 
old men. 

The following are the precepts which Dr. Weber formu- 
lated : All the organs must be preserved in a condition 
of vigour. It is necessary to recognise and subdue any 
morbid tendencies whether these be hereditary or have been 
acquired during life. It is necessary to be moderate in 
food and drink, and in all other physical pleasures. The 
air should be pure in the dwelling and in the vicinity. 
It is necessary to take exercise daily, whatever be the 
weather. In many cases the respiratory movements must 
be specially exercised, and exercise on level ground and 
up-hill should be taken. The persons should go to bed 
early and rise early, and not sleep for more than six or seven 
hours. A bath should be taken daily and the skin should 
be well rubbed, the water used being hot or cold, accord- 
ing to taste. Sometimes it is advantageous to use hot 
and cold water. Regular work and mental occupation are 
indispensable. It is useful to stimulate the enjoyment of 
life so that the mind may be tranquil and full of hope. On 
the other hand, the passions must be controlled and the 
nervous sensations of grief avoided. Finally, there must 
be a resolute intention to preserve the health, to avoid 
alcohol and other stimulants as well as narcotics and 
soothing drugs. 

By following his own precepts, Dr. Weber has enjoyed a 
vigorous and happy old age. A Mde. Nausenne, who died 
on March I2th, 1756, at the age of 125 years, in the Dinay 
Infirmary (C6tes-du-Nord) explained the secret of her still 
greater longevity as follows : " Extreme sobriety, no worry, 
body and mind quite calm " (Chemin, op. cit., p. 101). 

Hygienic measures have been the most successful in 
prolonging life and in lessening the ills of old age. 


Although until quite recently hygiene has rested upon a 
very small number of scientifically established facts, and 
although its precepts have not been followed rigidly, none 
the less it has already succeeded in increasing the dura- 
tion of human life. This becomes evident if we compare 
the mortality tables of the present day with those of the 

There is reason to state definitely that the mortality in 
civilised countries has decreased on the whole in the last 
one or two centuries. I have taken some facts regarding 
this from the valuable monograph of M. Westergaard. 1 
That author came to the conclusion that the mortality rate 
in the igth century in civilised countries was "much 
lower than in most earlier centuries." This diminution 
has been chiefly in infantile mortality. According to 
Mallet, the mortality rate of infants in the first year of 
their life was, in Geneva, 26 per cent, in the i6th century, 
and fell gradually to 16^ per cent, at the beginning of the 
igth century. A similar change has been reported from 
Berlin, Holland, Denmark and other places. However, 
it is not only very young infants that have shown a diminu- 
tion in the death-rate. The life of old people has been 
prolonged to an extent equally remarkable. The follow- 
ing are some of the facts which support this statement. 
Whilst the old Protestant clergymen of Denmark at ages 
varying from 74^ to 8g years had a mortality rate of 22 
per cent, in the second half of the i8th century, the rate 
had sunk to 16*4 per cent, by the middle of the igth 
century. This is not an isolated fact. The old clergymen 
of England (65 to 95 years) have also come to live longer, 
because in the i8th century the mortality rate was 11*5 
percent, and in the igth century (1800-1860) only io'8 per 
cent. There has been a similar decrease in the mortality 

1 Die Lehre -von d. Mortalitaet u. Mcrbilitaet, 2nd edition, Jena, 1901. 


rate in the members of both sexes of the Royal Houses 
of Europe (Westergaard, p. 284). 

From 1841 to 1850, in England and Wales i62'8i in- 
dividuals out of every thousand of both sexes died annually, 
but the corresponding figure for the period 1881 to 1890 
was decreased to 153 '67 per thousand. 

Westergaard (p. 296) has displayed in a most useful 
table the mortality in the chief countries of Europe and 
in the State of Massachusetts, in two periods of time. In 
the case of old persons from 70 to 75 years, there has 
been a constant decrease in the death-rate, without any 
exceptions. The exact statistics collected by Pension 
Bureaus and Life Assurance Companies exhibit the same 
general tendency. 

It cannot be disputed then that there has been a general 
increase in the duration of life, and that old people live 
longer at the present time than in former ages. This 
fact, however, cannot be taken absolutely, and it is still 
possible that in particular cases there may have been more 
centenarians hitherto than at present. 

The prolongation of life which has come to pass in 
recent centuries must certainly be attributed to the advance 
of hygiene. The general measures for the preservation 
of health, although they were not specially directed to old 
people, have had an effect of increasing their longevity. 
As in the i8th century and for the greater part of the 
1 9th, the science of hygiene was in a very rudimentary 
condition, we may well believe that improvement in clean- 
liness and in the general conditions have contributed largely 
to the prolongation of life. It is now a long time since 
Liebig said that the amount of soap used could be taken 
as a measure of the degree of civilisation of a people. As a 
matter of fact, cleanliness of the body brought about 
in the most simple way, by washing with soap, has had 


a most important effect in lessening disease and mor- 
tality from disease. In this connection, the fact recently 
published by Prof. Czerny, 1 a well-known German 
surgeon, has a special interest. Although cancer, the 
special scourge of old age, has increased in recent times, 
one form of the disease, cancer of the skin, has diminished 
notably. " Cancers of the skin," Prof. Czerny says, " are 
met with almost exclusively on uncovered regions of the 
body, or on parts accessible to the hands. They develop 
especially where the susceptibility is increased by ulcers 
or scars which are easily soiled. And so it happens that 
in the classes where care is taken as to cleanliness cancer 
of the skin is very rare and certainly much more rare 
than it used to be." 

M. Westergaard thinks that vaccination against small- 
pox has been of considerable importance in lowering the 
death-rate in the igth century. This, however, can have 
had little effect on the duration of life in old people, as 
deaths due to small-pox in the old are excessively rare. 
For instance, in the second half of the i8th century, that 
is to say before the introduction of Jenner's method, the 
mortality from small-pox at Berlin was 9'8 per cent, of 
all the deaths, but of these only o'6 per cent, were cases 
of persons more than fifteen years old. The rest, that is to 
say, 99*3 per cent, fell on children under that age. It 
may be supposed that most of the old people at that time 
were already protected by previous attacks of small-pox, 
contracted when they were young. 

If hygiene were able to prolong life when if was little 
developed, as was the case until recently, we may well 
believe that, with our greater knowledge of to-day, a much 
better result will be obtained. 

1 Medizinische Klinik, 1905, No. 22. 



Measures against infectious diseases as aiding in the pro- 
longation of life Prevention of syphilis Attempts to prepare 
serums which could strengthen the higher elements of the 

ATTACKS of infectious diseases incurred during life fre- 
quently shorten its duration and it has been observed that 
most centenarians have enjoyed good health throughout 
their lives. Syphilis is the most important of these dis- 
eases. It is not really a cause of death itself, but it pre- 
disposes the organism to the attacks of other diseases, 
amongst the latter being some particularly fatal to old 
people, such as diseases of the heart and blood-vessels 
(angina pectoris and aneurism of the aorta) and some 
malignant tumours, especially cancer of the tongue and 
of the mouth. To lengthen human life, it is a fundamental 
necessity to avoid infection by syphilis. To reach this 
result everything must be done to spread medical know- 
ledge about such diseases. It is absolutely necessary to 
overcome the deeply rooted prejudice in favour of con- 
cealing everything relating to sexual matters. Complete 
information should be widely spread as to the means of 
protecting humanity against this awful scourge. It has 
now been possible to apply experimental methods to the 


investigation of this disease, and science has obtained a 
series of results of the highest practical utility. Prof. 
Neisser of Breslau, one of the most distinguished of modern 
venereal physicians, has summed up the present state of 
knowledge of these matters in the following lines. 1 " It 
is our duty as medical men," he says, "to recommend 
strongly as a means of disinfection in all possible cases 
of contagion the calomel ointment which Metchnikoff and 
Roux have advised." It is to be hoped that future genera- 
tions, by following this advice, will see an enormous 
diminution in the number of cases of syphilis. 

Syphilis, however, although a very important factor, is 
not alone in shortening the life of man. A very large num- 
ber of persons die prematurely although they have not con- 
tracted that disease. We do not know the duration of 
human life before the arrival of syphilis in Europe, but 
there is no reason to think that it was very different from 
what it is to-day. We must, therefore, try to prevent as 
many infectious diseases as possible, and recent advances in 
medicine have made this task much less difficult. Pneu- 
monia, it is true, the most common infectious disease 
amongst the old, cannot yet be easily avoided. All the anti- 
pneumonic serums which have hitherto been prepared have 
turned out to have little efficacy ; but there is no reason to 
give up the hope that this problem will yet be solved. 

Diseases of the heart, which are common in extreme 
old age, are particularly difficult to avoid, because in most 
cases we do not know sufficiently well their primary causes. 
In so far as they depend upon intemperance or infectious 
diseases such as syphilis, they can be avoided by the em- 
ployment of suitable measures. 

As the higher elements of the body in old people become 
1 Die experimentelle Syphilisforschung, Berlin, 1906, p. 82. 


weaker and are devoured by the macrophags, it seems 
probable that the destruction or deterioration of these 
voracious cells would tend to the prolongation of life. 
However, as the macrophags are indispensable in the 
struggle against the microbes of infectious diseases, and 
particularly of chronic disease, such as tuberculosis, it is 
necessary to preserve them. We must turn rather to the 
idea of a remedy which could strengthen the higher 
elements and make them a less ready prey to the macro- 

In the " Nature of Man " (Chap. III.) in discussing the 
simian origin of mankind, I touched on the existence of 
animal serums that have the power of dissolving the 
blood corpuscles of other species of animals. There is 
now, in biological science, a new chapter upon such 
serums, which have been called cytotoxic serums because 
they are able to poison the cells of organs. 

The blood and blood serum of some animals act as 
poisons when they are introduced into an organism. Eels 
and snakes, even non-poisonous snakes, are cases in point. 
A small quantity of the blood of a snake, an adder for 
instance, injected into a mammal (rabbit, guinea-pig, or 
mouse) soon brings about death. The blood of some 
mammals is poisonous to other mammals, although in a 
lesser degree than that of snakes. The dog is specially 
notable from the fact that its blood is poisonous to other 
mammals, whilst, on the other hand, the blood and blood 
serum of the sheep, goat, and horse have generally little 
effect on other animals and on man. It is for this reason 
that these animals, and particularly the horse, are used in 
the preparation of the serums employed in medicine. 

Now, these harmless serums become poisonous when 
they have been taken from animals which have been first 

L 2 


treated with the blood or the organs of other species of 
animals. For instance, the blood serum of a sheep which 
has been treated with the blood of a rabbit becomes 
poisonous because it has acquired the power of dissolving 
the red blood corpuscles of the rabbit. It is a poison in 
the case of the rabbit, but is harmless to most other 
animals. The injection of the rabbit's blood into the sheep 
has conferred on the sheep a new property which comes 
into operation only with regard to the red blood corpuscles 
of the rabbit. We have here to do with something analo- 
gous to what has been observed in the cases of serums 
used to arrest infectious disease. When the bacilli of 
diphtheria, or their products, have been injected into 
horses, there is produced an anti-diphtheric serum, capable 
of curing diphtheria, but powerless against tetanus or 
plague. After M. J. M. Bordet of the Pasteur Institute 
had made his discovery of serums that had acquired 
the power of dissolving the red blood corpuscles of other 
animals, the attempt was made to prepare similar serums 
directed against all the other elements of the body, such 
as white blood corpuscles, renal and nervous cells. In 
the course of these investigations it was proved to be neces- 
sary to employ a certain dose of the serum in order to 
obtain the poisonous result. If smaller quantities of the 
poisonous dose were used, the reverse effect was produced. 
Thus a serum, strong doses of which dissolved the red 
blood corpuscles and so made them less numerous in the 
blood, increased the number of these when given in very 
small doses. 

M. Cantacuzene was the first to establish this fact in 
the case of the rabbit, whilst M. Besredka and I myself 
did it in the case of man. 1 Since then M. Belonovsky of 
1 Annales de VInstitut Pas/eitr, 1900, pp. 369-413. 


Cronstadt has confirmed the result on anaemic patients, 
treating them with small quantities of serum. He has 
been able to produce in them an increase in the number 
of the red blood corpuscles, and in the quantity of the red 
colouring matter (haemoglobin) in the blood. Later on 
M. Andre 1 devoted much attention to this matter at 
Lyons. He prepared a serum by injecting human blood 
into animals and made use of it in the case of several 
persons who suffered from anaemia from different causes. 
In the case of patients, the anasmic condition of which had 
hitherto remained stationary, Dr. Andre found a sudden 
increase in the number of red corpuscles after injecting 
small doses of the serum. M. Besredka, in the case of 
laboratory animals, increased the number of white cor- 
puscles by injecting them with a small quantity of a serum, 
strong doses of which destroyed these cells. 

These facts are only a special case of the general rule 
that small doses of poisons increase the activity of the 
elements that are killed by large doses. In order to 
increase the activity of the heart, medical men give success- 
fully small doses of cardiac poisons such as digitalis. 
As a commercial process, the activity of yeasts is increased 
by submitting them to weak doses of substances (fluoride 
of sodium) which, given in larger quantities, would kill 

My general conclusion from these facts is that it is 
logical to lay down the principle that the higher elements 
of our body could be strengthened by subjecting them to 
the action of small doses of the appropriate cytotoxic 
serums. There is, however, much difficulty in putting 
this into practice. It is quite easy to obtain human blood 
to inject into animals with the object of preparing a serum 
1 Les serums hemolytiques, Lyon, 1903. 


which can increase the number of red corpuscles. On the 
other hand, it is extremely difficult to get human bodies 
sufficiently fresh to use them for a practical purpose. 
According to law, post mortem examinations can be made 
only after an interval of time in course of which the tissues 
have changed ; besides, the organs obtained in this way are 
frequently affected by injuries or diseases militating 
against their use. Even in Paris, with its three million 
inhabitants, it is extremely rare that there is a good oppor- 
tunity for the preparation of human cytotoxic serums. 
In two or three years, during which Dr. Weinberg has 
collected the organs from human bodies fairly fresh, he 
has been unable to obtain sufficiently active serums. 

The best results have been obtained from new-born 
infants which have been killed by some accident in the 
process of child-birth, as in them the organs are in a 
normal state. However, owing to the advance in the 
practice of obstetrics, such accidents, already infrequent, 
are becoming extremely rare. In such conditions we 
may have to wait long before getting a positive result, 
unless the future will find some method of obtaining the 
necessary materials for this difficult and interesting 

As it is so difficult to prepare a remedy which can 
strengthen the weakened higher elements of the body, it 
may be easier to find a means of preventing the weakening 
which interferes so much with our desire to live long. 
As the products of microbes are the most active agents in 
deteriorating our tissues, we must look towards them for 
the solution of the problem. 



Uselessness of the large intestine in man Case of a woman 
whose large intestine was inactive for six months Another 
case where the greater part of the large intestine was com- 
pletely shut off Attempts ti disinfect the contents of the 
large intestine Prolonged mastication as a means of 
preventing intestinal putrefaction 

THE general measures of hygiene directed against infec- 
tious diseases play a part in prolonging the lives of old 
people, but, in addition to the microbes which invade the 
body from outside, there is a rich source of harm in the 
microbes which inhabit the body. The most important 
of these belong to the intestinal flora, which is abundant 
and varied. 

The intestinal microbes are most numerous in the large 
intestine. This organ, which is useful to mammals the 
food of which consists of rough bulky vegetable matter, 
and which require a large reservoir for the waste of the 
process of digestion, is certainly useless in the case of 
man. 1 In the " Nature of Man " I have dealt with this 

1 According to a recent publication of M. Ellenberger (Archiv. /. 
Anatomie u. Physiologic, Physiologische Abtheilung, 1906, p. 139), the 
caeca of the horse, pig and rabbit, play an active part in the digestion 
of vegetable matter, which is rich in cellulose. At the end of his 
treatise, Ellenberger insist that the vermiform appendix of the caecum 
is not a rudimentary organ. The reason why the appendix can be 


question at length, as it was an important example of 
what I regard as the disharmonies of the human constitu- 
tion. A case upon which I have always laid great stress 
is that of a woman who lived for thirty-seven years, 
although her large intestine was atrophied and inactive, as 
this seems to be a remarkable proof of the uselessness of 
the organ in the human body. The small size or complete 
absence of the large intestine in many vertebrates confirms 
my conclusion. None the less, some of my critics think 
that my argument is incomplete. To strengthen it, I may 
call their attention to a medical observation which is as 
valuable as if it had been an experiment. It relates to a 
woman, sixty-two years old, a patient of Prof. Kocher at 
Berne. She had been suffering from a strangulated hernia 
associated with gangrene of part of the intestine, and had 
to be operated upon suddenly , 

The gangrenous portion of the ileum having been re- 
moved, the healthy part was implanted in the skin so as 
to form an artificial aperture through which waste matter 
from the food passed to the exterior without traversing the 
large intestine. Although the patient was old and seriously 
ill, the operation, performed by M. Tavel, was quite suc- 
cessful. Six months later, in a new operation, the small 
intestine was rejoined to the large intestine so that the 
faeces were again able to pass to the exterior by the natural 
channel. In this case, then, the large intestine was thrown 
out of use for half a year, not only without injury to the 
general health, but with the result that the patient was corn- 
removed in the case of man without disturbance to the functions of 
the body, is that this work can be performed by the Peyer's patches of the 
intestine. The existence of the appendix is not necessary to the normal 
processes of the body, and is a real danger to health and sometimes 
to life. Comparative study of the caeca in birds shows that these organs 
are in process of degeneration. 


pletely cured and gained in weight. MM. Macfadyen, 
Nencki, and Mde. Sieber J studied the digestive processes 
in the small intestine and the nutritive metabolism, and 
determined that these were active and healthy, the absence 
of intestinal putrefaction, that evil of the constitution, being 
specially favourable. 
In six months of non-action, the part played by an organ 

FIG. 19. Diagram of the lower bowel in a female patient. 

A.C.N., Artificial anus : A.S., Insertion of the ileum to the colon. 

(After M. Mauclaire.) 

can be satisfactorily estimated. M. Mauclaire, 2 however, 
has put on record a case the history of which was longer. 
In 1902 he operated on a young woman and produced an 
artificial anus, there being no escape of faecal' matter by 
the ordinary channel. Ten months later M. Mauclaire 
operated a second time and shut off a portion of the intes- 
tine. He left the artificial anus, but cut across 

1 Archiv.fur experimented Pathologic, vol. xxviii, p. 311. 

2 Sixtime Congrh <fe Chirurgic, Paris, 1903, p. 86. 



the lower end of the small intestine and inserted 
it near the iliac end of the descending colon (Fig. 
19). For several days after the operation the faces 
were passed by the normal aperture, as the small intes- 
tine now communicated directly with the large intestine, 
near the rectum. This condition, however, did not persist, 
for the faecal matter began to flow back through the ex- 
cluded portion of the large intestine, so reaching the artifi- 

FIG. 20. Diagram of the lower bowel, after a third operation, on the case 

in Fig. 19. 
(After M. Mauclaire.) 

cial anus, and causing inconvenience. Giving up the hope 
that this would cease, M. Mauclaire performed a third 
operation twenty months later. He cut across the large 
intestine near the point vvrfiere the small intestine had been 
artificially led into it (Fig. 20), so dividing the digestive 
tube into two parts, one of which remained in communica- 
tion with the natural anus, whilst the other, consisting of 


nearly the whole of the large intestine, communicated with 
the exterior by the artificial anus. In the new state of 
affairs, the food refuse passed directly into the terminal 
portion of the large intestine, and thence, by way of the 
rectum, to the exterior through the normal anus without 
being able to pass up the large intestine towards the arti- 
ficial anus. In this last operation about a yard of the small 
intestine and the greater part of the large intestine, the 
caecum, and ascending, transverse and descending colons 
were removed from activity. 

By the kindness of M. Mauclaire, I have been able to 
watch his patient during the last four years. I satisfied 
myself that after the supposed exclusion of the large intes- 
tine, food dejecta ascended the colon and emerged by the 
artificial anus. There was such an accumulation of waste 
in the large intestine that fragments did not emerge until 
three, weeks after the meal of which they had formed part. 
It was only after the final operation, that in which the large 
intestine was separated, that the dejecta escaped only by the 
natural anus, whilst a little mucus containing microbes was 
passed through the artificial aperture. Even three years 
after the operation, mucus continued to escape by the latter 
aperture, it being shown thus that after the large intestine 
had ceased to be a channel for the faeces, its walls continued 
to secrete although otherwise it had lost its function com- 
pletely. Nevertheless the condition of this patient improved 
and she 'lived perfectly well without a functional large in- 
testine. She takes food well but has to go to stool three 
or four times a day and has a tendency to diarrhoea. The 
excreta are smooth and often nearly liquid, especially after 
fruit has been eaten. 

The case I have been describing, and which I am still 
keeping under observation, demonstrates once more the use- 
lessness of the human large intestine; it should convert the 


most sceptical critic. But it also shows that the suppres- 
sion of nearly the entire large intestine for several years 
does not completely get rid of the intestinal flora. Even 
without this evidence, however, I do not suggest that re- 
moval of the large intestine can be thought of as a means to 
prevent the pernicious effect of the intestinal flora. 

Is it possible, without operative interference, to take 
direct action against the intestinal flora by the use of anti- 
septics ? Consideration of this is already ancient history. 
When the theory that the intestine was a source of auto- 
intoxication was propounded, M. Bouchard 1 made the at- 
tempt to cure such cases by disinfecting the digestive tube 
with /9-naphthol. He found, however, that that anti- 
septic, like many others, not only did not completely dis- 
infect the intestine but sometimes had a harmful effect on 
the body. 

M. Stern 2 has shown, in an elaborate memoir, that such 
antiseptics as calomel, salol, /S-naphthol, naphthaline, and 
camphor, when administered in quantities compatible with 
health, do not disinfect the digestive tube at all. More 
recently M. Strasburger 3 has shown that when naphthaline 
has been given in quantities sufficient to impart its odour to 
the faeces, the intestinal microbes, so far from being dimin- 
ished, are even increased in numbers. On the other hand, 
after meals consisting of milk to which there has been 
added an antiseptic in the proportion of a quarter of a gram 
to the litre, the intestinal microbes are really reduced in 
number. Strasburger obtained his best results with tano- 
col. Two persons who used, according to this method, 
three to six grams of tanacol per day, displayed a notable 
reduction in quantity of the intestinal flora. 
Strasburger's conclusion was that " the attempt to destroy 

1 Lemons sur les auto-intoxications, Paris, 1886. 

Zeitschrift fitr Hygiene, 1892, vol. xii, p. 88. 

ZeitschrifUfiirkliniache Median, 1903, vol. xlviii, p. 491. 


the intestinal microbes by the use of chemical agents has 
little chance of success." It cannot be denied that under 
special circumstances it is possible to decrease the number 
of microbes, especially in the small intestine. But this 
result is small and may be followed by the contrary effect, 
for the natural means of defence of the intestine against 
microbes are weakened, and the intestine itself may be 
harmed more than the microbes. 

Strasburger, moreover, is no convinced advocate of the 
use of purgatives. The diminution of the sulpho-con jugate 
ethers in the urine, which certainly may follow the 
use of purgatives, does not necessarily indicate reduced 
putrefaction in the intestine, but may point only to a less- 
ened absorption of the bacterial products. Such an inter- 
pretation is supported by an observed fact ; in the case of a 
dog belonging to Strasburger, which had a fistula of the 
small intestine, the diarrhoea induced by calomel was ac- 
companied by an indubitable increase in the total quantity 
of intestinal microbes. 

Strasburger thinks that the most favourable results can 
be obtained by aiding the intestine in the discharge of its 
normal function. If it can be brought to digest the food 
more completely, there is the less pabulum left for the 
microbes. A similar result can be reached by lowering the 
amount of food taken, and to this course the beneficial 
effects of starvation in acute diseases of the intestine may 
be attributed. 

The general conclusion, reached after many experiments 
on the disinfection of the intestine, is unfavourable. Very 
little is to be expected from the method. None the lessI 
cannot regard the matter as definitely settled. Cohendy 
has investigated the effect on the intestinal flora of thymol 
which was administered in several cases with the object 


of destroying parasites. From nine to twelve grammes of 
thymol were administered to each patient in the space of 
three days, and there was a notable antiseptic effect, 
Cohendy believing that the quantity of microbes had been 
reduced to a thirteenth. 

Such facts prove only that the antiseptic treatment is 
available up to a certain point. To attain the results, how- 
ever, such large quantities must be used that the treatment 
can be applied only in special cases and at long intervals. 
More use can be made of simple purgatives which do not 
kill the microbes but eliminate them by the normal channel. 
It has been urged repeatedly that calomel, which is often 
used as a purgative, acts also as an intestinal antiseptic ; 
but it is probable that its influence in reducing the intes- 
tinal flora is merely mechanical. It has been shown that 
calomel, like some other purgatives, lessens intestinal 
putrefaction, the evidence being the decrease in the 
sulpho-conjugate ethers in the urine. But although the 
diarrhoea induced by purgatives generally has such a result, 
spontaneous diarrhoeas such as those of typhoid fever and 
of intestinal tuberculosis are associated with increased 
putrefaction. 1 

It is clear, however these matters may be settled, that 
regular activity of the bowels, increased by the occasional 
use of purgatives, must diminish the formation of intestinal 
poisons, and therefore also the damage done by these to 
the higher elements of the body. 

When I asked the relatives of Mde. Robineau if they 
could tell me of any special circumstance which in their 
opinion had contributed to the extreme duration of the life 

1 There is a summary of this question in Gerhardt's work on intes- 
tinal putrefaction, in Ergebnisse der Physiologic, 3rd year, section i, 
Wiesbaden, 1904, pp. 107-154. 


of this old lady, they replied as follows : " We are con- 
vinced that a slight bodily derangement, present for the last 
fifty years, has tended to prolong the life of the old lady. 
It cannot be said that she has suffered from diarrhoea, but 
she has been often subject to frequent calls of nature." It 
was most remarkable that the old lady showed no traces of 
sclerosis of the arteries. I may mention the strongly con- 
trasting case of one of my old colleagues to whom a natural 
desire to empty the bowels came only once a week. A 
more frequent call was a sign of illness in his case. Now 
sclerosis of the arteries appeared in so marked a form that 
he died from it before he had reached the age of fifty years. 
This may be added to the list of facts which point to a 
close association between sclerosis of the arteries and the 
functions of the digestive tube. 

Recently, at the suggestion of Mr. Fletcher, 1 the advan- 
tage of eating extremely slowly has been recognised, the 
object being to prepare for the utilisation of the food mate- 
rials, and to prevent intestinal putrefaction. Certainly the 
habit of eating quickly favours the multiplication of 
microbes round about the lumps of food which have been 
swallowed without sufficient mastication. It is quite harm- 
ful, however, to chew the food too long, and to swallow it 
only after it has been kept in the mouth for a considerable 
time. Too complete a use of the food material causes want 
of tone in the intestinal wall, from which as much harm 
may come as from imperfect mastication. In America, 
where Fletcher's theory took its origin, there has already 
been described under the name of " Bradyfagy" a disease 
arising from the habit of eating too slowly. Dr. Einhorn^ 8 

1 The A B C of our Nutrition^ New York, 1903 ; Dr. Regnault, Nov. 
I, " L'art de manger," La Revue, 1906, p. 92. 
* Zeitschr.f. diatetischev.physikal. Therapie^. viii, 1904, 1905. 


a well-known specialist in the diseases of the digestive sys- 
tem, has found that several cases of this disease were 
rapidly cured when the patients made up their minds to eat 
more quickly again. Comparative physiology supplies us 
with arguments against too prolonged mastication. Rumi- 
nants, which carry out to the fullest extent Mr. Fletcher's 
plan, are notable for extreme intestinal putrefaction and for 
the short duration of their lives. On the other hand, birds 
and reptiles, which have a very poor mechanism for break- 
ing up food, enjoy much longer lives. 

Prolonged mastication, then, cannot be recommended as 
a preventative of intestinal putrefaction any more than the 
surgical removal of the large intestine or the disinfection of 
the digestive tube. The field lies open for other means 
which may probably solve the problem more completely 
and more practically. 


The development of the intestinal flora in man Harmless- 
ness of sterilised food Means of preventing the putrefaction 
of food Lactic fermentation and its anti-putrescent action 
Experiments on man and mice Longevity in races which 
use soured milk Comparative study of different soured 
milks Properties of the Bulgarian Bacillus Means of pre- 
venting intestinal putrefaction with the help of microbes 

AT birth the human intestine is full, but contains no 
microbes. Microbes very soon appear in it, because the 
meconium, the contents of the intestines of new-born chil- 
dren, composed of bile and cast-off intestinal mucus cells, 
is an excellent culture medium for them. In the first hours 
after birth, microbes begin to reach the intestine. In the 
first day, before the child has taken any food whatever, 
there is to be found in the meconium a varied flora, com- 
posed of several species of microbes. Under the influence 
of the mother's milk this flora is reduced and comes to be 
composed almost entirely of a special microbe described by 
M. Tissier and called by him Bacillus bifidus. 

The food, therefore, has an influence on the microbes of 
the intestine. If the child be fed with cow's milk, the flora 
is richer in species than in the case of a child suckled by 
its mother. Later on, also, the flora varies with the food, 
as has been proved by MM. Macfadyen, Nencki, and Mde. 



Sieber in the case of a woman with an intestinal fistula. 
The dependence of the intestinal microbes on the food 
makes it possible to adopt measures to modify the flora in 
our bodies and to replace the harmful microbes by useful 
microbes. Unfortunately, our actual knowledge of the in- 
testinal flora is still very imperfect because of the impos- 
sibility of finding artificial media in which it could be 
grown. Notwithstanding this difficulty, however, a 
rational solution of the problem must be sought. 

Man, even in the savage condition, prepares his food be- 
fore eating it. He submits much of it to the action of fire, 
thus notably lessening the number of microbes. Microbes 
enter the digestive tube in vast numbers with raw food, 
and in order to lessen the number of species in the 
intestines, it is important to eat only cooked food and to 
drink only liquids that have been previously boiled. In 
that way, although we cannot destroy all the microbes in 
the food, because some of them can withstand the tempera- 
ture of the boiling point of water, we can kill the great 
majority of them. 

It has sometimes been supposed that cooked or com- 
pletely sterilised food (that is to say food that has been 
subjected to a temperature of from 248-284 Fahr.) is 
harmful to the organism and that much of it is not well 
digested. From this point of view protests have been 
made against the feeding of infants with sterilised milk 
or even with boiled milk. Although in certain cases steril- 
ised milk is not well supported by infants, it cannot be 
doubted but that boiled milk and cooked food are generally 
successful. The large number of children brought up suc- 
cessfully on boiled cow's milk and the health of travellers 
in arctic regions are ample proof of this. I have been 
told by M. Charcot that in his voyage to the antarctic 


regions, he and his companions lived entirely on sterilised 
food, or on cooked food such as the flesh of seals and 
penguins. As they had no green food nor fresh fruit, the 
only raw food that they ate was a little cheese. Living 
under these conditions, all the members of the expedition 
enjoyed good health, and there was no case of digestive 
disturbance in the whole period of sixteen months. 

It is obvious that abstaining from raw food, and so 
reducing largely the entrance of new microbes, by no 
means causes the disappearance of the intestinal flora 
already existing. We must reckon with that and with 
the evil that it does by weakening the higher cells of the 
tissues. As the part of the flora that does most damage 
consists of microbes which cause putrefaction of the con- 
tents of the intestine and harmful fermentations, particu- 
larly butyric fermentation, it is against these that our 
efforts must be directed. 

Long before the science of bacteriology was in exist- 
ence, men had turned their attention to methods of pre- 
venting putrefaction. Food, especially if it be kept in a 
warm place or in a moist atmosphere, soon begins to 
putrefy and to become unpleasant to the taste and danger- 
ous to the health. Everyone has known cases of poison- 
ing from putrid flesh or other food material. Foa, 1 the 
explorer of Central Africa, has related that once, when 
they were starving, he and his men came on the putrefying 
body of an elephant. The negroes rushed to lay hold of 
the carrion, but Foa tried to dissuade them, explaining 
that to eat flesh in such a state was as bad as taking 
poison. All did not listen to him, and three negroes, who' 
had taken pieces of the body, swallowed them before they 
had been properly cooked. All three died in a few days, 
1 Du Cap au lac Nyassa, Paris, 1897, pp. 291-294. 

M 2 


with the neck and throat swollen, the tongue almost para- 
lysed, and the abdomen inflated. 

In another case, sausages made of putrid horse flesh 
caused an epidemic at Rohrsdorf, in Prussia, in I885. 1 
About forty people fell ill after having eaten the sausages, 
which, according to witnesses, were green in colour, smelt 
badly, and had a revolting appearance. One person died, 
whilst the others recovered after cholera-like symptoms. 
It is true that all putrefying food does not produce the 
same effect. MM. Tissier and Martelly 2 found no diges- 
tive trouble after having eaten food that was quite putrid. 
Everyone knows that the Chinese prepare a dish particu- 
larly pleasant to gourmets by allowing eggs to putrefy. 
Some decaying cheeses are harmful to the health, but 
others can be eaten with impunity. The reason of this 
is that whilst putrefying food may contain microbes and 
dangerous toxins, it does not contain them in all cases. 
On the other hand, we must take into account the different 
susceptibilities of people to the harmful action of microbes 
and their products. Some can swallow without any evil 
result a quantity of microbes which in the case of other 
individuals would produce a fatal attack of cholera. Every- 
thing depends upon the resistance offered to the microbes 
by the invaded organism. 

Experiments on animals fed on putrefying food have 
also given varied results. Some animals eat it without 
any harm resulting, others have attacks of vomiting and 
show such a repugnance that it is impossible to continue 
the experiment. 

Not only flesh and other animal substances, but vege- 
tables can undergo putrefaction and fermentation (butyric) 

1 Gaffky and Paak, in Arbeiten d. k. Gesundheitsamtes, vol. vi, 1890. 

2 Annales de flnstitui Pasteur, 1903. 


which make it dangerous to eat them. Many accidents 
have occurred in man as the result of deteriorated pre- 
served fruit. Vegetables, preserved in silos to feed cattle, 
sometimes go wrong. "If, for instance, rainy days come 
after sunny days, so that the uncovered fodder is wetted 
again, the resulting ensilage is poor and has an extremely 
unpleasant butyric odour, so that the animals turn from it." 
Sometimes the fodder grows black in the silo, and acquires a 
special smell. "The animals will take it only in the 
absence of other food ; their excreta become black, and if 
they are kept on such a diet for a time they waste in a 
marked manner." 1 

In popular practice, the value of acids for preserving 
animal and vegetable food and for preventing putrefaction 
has long been recognised. Meats of all kinds, fish and 
vegetables have been " marinated " with vinegar, as the 
acetic acid in that substance, the product of bacteria, 
wards off putrefaction. If the materials which it is desired 
to preserve give off acids themselves, the addition of 
vinegar may be unnecessary. For this reason some animal 
products such as milk, or vegetables rich in sugar become 
acid spontaneously and so can be preserved. Soured 
milk can be made into many kinds of cheese, and these 
last for longer or shorter times. Many vegetables can 
undergo a natural process of souring, when they "keep" 
without difficulty. Thus cabbage becomes " sauer-kraut " 
and beetroot and cucumbers pass into an acid state. In 
many countries, as for instance in Russia, the use of acidi- 
fied vegetables is of great importance in the food-supply 
of the populace. Fresh fruit and vegetables cannot be 
obtained in the long winters, during which the people con- 

1 Cormouls-Houlfcs, Vingt-sept ann&s ^agriculture pratique, Paris, 
1899, PP- 57-58. 


sume large quantities of cucumbers, melons, apples, and 
other fruits which have undergone an acid fermentation 
in which lactic acid is the chief product. During summer, 
milk, which acidifies readily, is the chief source of acid 
materials for consumption. The chief beverage is 
"kwass," of which black bread is the main ingredient, 
and this passes through not only an alcoholic fermentation, 
but an acidifying change in which lactic acid is the most 
important product. 

Rye bread, the chief food of the populace, is also a 
product of fermentations amongst which the lactic acid 
fermentation is most important, but in other kinds of bread 
also there is a fermentation in which some of the sugar 
is transformed to lactic acid. 

Soured milk, because of the lactic acid in it, can impede 
the putrefaction of meat. In certain countries, accord- 
ingly, meat is preserved in acid skimmed milk with the 
result that putrefaction is prevented. Lactic acid fermenta- 
tion is equally important in the food supply of cattle. It 
is the chief agent that, in the process of preserving vege- 
tation in silos, hinders putrefaction. Finally, the same 
fermentation serves in distilleries to preserve the must from 
which alcohol is prepared. 

This short review is in itself enough to show the great 
importance of lactic fermentation as a means of stopping 
putrefaction and butyric fermentation, both of which hinder 
the preservation of organic substances and are capable 
of exciting disturbances in the organism. 

As lactic fermentation serves so well to arrest putrefac- 
tion in general, why should it not be used for the same 
purpose wiihin the digestive tube? 

It is a matter of common knowledge that putrefaction 
and butyric fermentation are arrested in the presence of 


sugar. Whereas meat preserved without special care soon 
putrefies, milk in exactly the same conditions does not 
putrefy, but becomes sour, the reason being that meat is 
poor in sugar whereas milk contains a good deal of it. 
However, the scientific explanation of this fundamental 
fact is difficult. It has been shown conclusively that sugar 
itself cannot prevent putrefaction. Milk, for instance, how- 
ever rich in sugar it may be, readily putrefies in certain 
conditions. Sugar preserves organic matter from putre- 
faction only because it can readily undergo lactic fermenta- 
tion, and this fermentation is the work of the microbes 
described fifty years ago by Pasteur. That great dis- 
covery proved the part played by microbes in fermenta- 
tion and founded bacteriology, a science equally rich in 
theory and in practice. 

I need not pause to develop the theme that the anti- 
putrescent action of the lactic fermentation depends on the 
production of lactic acid by microbes, because I have 
explained the matter at length in the tenth chapter of the 
" Nature of Man." If the lactic acid be neutralised, the 
organic matter soon putrefies, notwithstanding the pre- 
sence of the lactic microbes. The most important point 
is as to whether lactic fermentation really arrests intestinal 
putrefaction. Several sets of observations have been made 
upon this matter. Dr. Herter, 1 of New York, injected 
directly into the small intestine of a number of dogs 
quantities of different microbes. To test the action of 
these on intestinal putrefaction, he investigated the sulpho- 
conjugate ethers in the urine, as he believed, in accord- 
ance with current and well justified opinion, that 
these substances are the best proofs of the existence of 
putrefaction. He found that whilst the introduction of 
1 British Medical Journal, 1897, Dec. 25th, p. 1898. 


quantities of Bacillus coli or Bacillus proteus increased the 
intestinal putrefaction, lactic bacilli notably lessened it. 
Herter found a notable diminution of sulpho-conjugate 
ethers in the urine of dogs which had been treated with 
the lactic microbes. 

The experiments which Dr. M. Cohendy 1 performed 
upon himself during a period of nearly six months are 
still more interesting. 

When Dr. Cohendy had proved that much intestinal 
putrefaction occurred during a period of 25 days, in which 
he lived on an ordinary mixed diet, he began to take pure 
cultures of lactic bacillus, taken from yahourth. In a 
period of 74 days, he took quantities varying from 280 
to 35 grams of the culture. 

Analysis of the urine during the progress of the experi- 
ment showed that intestinal putrefaction had notably de- 
creased whilst the lactic bacilli were being taken, and that 
the diminution persisted seven weeks after the taking of 
the bacilli ceased. Dr. Cohendy gives it as the direct 
result of his experiment that the introduction of lactic 
ferment into the intestine definitely arrests putrefac- 
tion. He obtained this result on a diet consisting of 400 
grams of soup, 150 of meat, 700 of grain-food, 400 of 
green vegetables, 300 of fruits and dessert and a litre of 
water. He came to the conclusion that the elimination of 
meat from the diet was unnecessary, as the particular kind 
of lactic ferment he employed was extremely active in in- 
hibiting the proteolytic ferments. 

Later experiments made by Dr. Cohendy showed that 
the lactic bacillus became so acclimatised in the human 
intestine that it was to be found there several weeks after 
it had been swallowed. 

1 Cotnptes rendus de la Soc. de Biologic, 1906, March i;th. 


Dr. Pochon, assistant to Professor Combe l at Lausanne, 
has repeated on himself the experiments of Cohendy. He 
took for several weeks milk curdled with pure cultures of 
lactic acid microbes and obtained " results that were quite 
definite as to intestinal putrefaction." Analysis of his 
urine showed that there was a marked diminution of indol 
and phenol, substances which are certain indexes of in- 
testinal putrefaction. 

In addition to such observations on lactic bacilli there 
is a good deal of knowledge as to the effect of lactic acid 
taken in bulk. The result of the various observations 2 
shows that the acid lessens intestinal putrefaction and 
lowers the quantity of sulpho-conjugate ethers in the 
urine. This fact explains why favourable results follow 
the use of lactic acid in many intestinal diseases such as 
infantile diarrhoea, tuberculous enteritis and even Asiatic 
cholera. The addition of this remedy to practical thera- 
peutics is due chiefly to Professor Hayem. It is employed 
not only in the treatment of diseases of the digestive 
system (dyspepsia, enteritis and colitis), but is indicated 
also in diabetes and is used locally in tuberculous ulcera- 
tions of the larynx. As quantities up to twelve grams 
can be given by the mouth daily, it is plain that the system 
is tolerant of this acid. It is either oxidised in the tissues 
or excreted with the urine. In the case of a 
diabetic woman who had taken 80 grams of lactic acid 
in four days, Nencki and Sieber 3 found no traces of it 

1 Dr. Combe, L'auto intoxication intestinale, Paris, 1906. This valuable 
work contains much useful information on the subject. ,, 

2 Grundzach, Zeitschrift fur klinische Medezin, 1893, P- 7 : Schmitz, 
Zeitschrift fur physiologiscfte Chemie, 1894, vol. xix, p. 401 ; Singer, 
Therapeulische Monatshefte, 1901, p. 441. 

J Journal fitrpraktische Chemie, 1882, vol. xxvi, p. 43. 


in the urine. On the other hand, Stadelmann 1 found a 
notable quantity of the acid in another diabetic patient 
who had been taking over four grams daily. 

The general interpretation of the benefits gained from 
the use of lactic acid ferments is that they depend solely 
on the action of the lactic acid which they produce in 
preventing the multiplication of the microbes which cause 
putrefaction. Recent investigations made by Dr. Belon- 
owsky, at the Pasteur Institute, show that a lactic ferment 
isolated from yahourth and described as the Bulgarian 
bacillus owes its antiseptic powers not only to lactic acid 
but to another substance which it secretes. Dr. Be"lon- 
owsky has studied the effects of this bacillus upon mice, by 
adding to their previously sterilised food quantities of 
this lactic microbe. As control experiments he fed other 
mice on food to which lactic acid had been added in 
quantities corresponding to the quantity produced by the 
Bulgarian bacillus, or which had been mixed with other 
kinds of bacilli. Another set of mice were given normal 
food without the addition of either microbes or lactic 

Out of these groups of mice, those which had been given 
the Bulgarian bacillus thrived best and had most progeny. 
Their droppings showed fewest microbes, particularly 
microbes of putrefaction. 

The next stage in Dr. Belonowsky's experiments was 
to feed mice not with living quantities of the Bulgarian 
bacillus, but with cultures which had been sterilised by heat 
(i2o-i4o Fahr.). These mice lived as well as those to 
which living cultures had been supplied, and notably better 
than those supplied with pure lactic acid. It is evident 
therefore that there is some other product of this 
1 Atchiv.furexperimentelle Pathologic, 1883, vol. xvii, p. 442. 


bacillus which favours life by preventing intestinal 

Dr. Belonowsky showed, moreover, that the Bulgarian 
bacillus cures a special intestinal disease known as mouse 

The experiments which I have described show that in- 
testinal putrefaction is to be combated not by lactic acid 
itself, but by the introduction into the organism of cultures 
of the lactic bacilli. The latter become acclimatised in 
the human digestive tube as they find there the sugary 
material required for their subsistence, and by producing 
disinfecting bodies benefit the organism which supports 

From time immemorial human beings have absorbed 
quantities of lactic microbes by consuming in the uncooked 
condition substances such as soured milk, kephir, sauer- 
kraut, or salted cucumbers which have undergone lactic 
fermentation. By these means they have unknowingly 
lessened the evil consequences of intestinal putrefaction. 
In the Bible soured milk is frequently spoken of. When 
Abraham entertained the three angels he set before them 
soured milk and sweet milk and the calf which he had 
dressed (Genesis xviii. 8). In his fifth book, Moses 
enumerates amongst the food which Jehovah had given 
his people to eat " Soured milk of kine and goat's milk, 
with fat of lambs and rams of the breed of Bashan, and 
goats with the fat of kidneys" (Deut. xxxii. I4). 1 

A food known as " Leben raib," which is a soured milk, 
prepared from the milk of buffaloes, kine or goats, has 

1 In the English authorised version as in the translation of Oster- 
wald the word " butter " is used in place of " soured milk." Professor 
Metchnikoff follows the translation given by Ebstein in his work on 
the Medicine of the Old Testament. 


been used in Egypt from the remotest antiquity. A similar 
preparation known as "yahourth" is familiar to the 
populations of the Balkan Peninsula. The natives of 
Algiers make a kind of " leben " not identical with the 
Egyptian form. 

Soured milk is consumed in great quantities in Russia 
in two forms, " prostokwacha," which is raw milk spon- 
taneously coagulated and soured, and " varenetz," which 
is boiled milk soured with a yeast. 

The chief food of many natives of tropical Africa con- 
sists of soured milk. The staple diet of the Mpeseni is 
" a curdled milk, almost solidified." " Meat is eaten only 
on ceremonial occasions." According to Foa, a tribe of 
the Nyassa-Tanganyika plateau, like the Zulus, take milk 
only in the form of a raw cheese mixed with salt and 

Dr. Lima of Mossamedes, in West Africa, has told me 
that the natives of many regions south of Angola live 
almost entirely on milk. They employ the cream as an 
ointment for the skin, whilst the milk, soured and curdled, 
is their staple food. M. Nogueira reported the same cir- 
cumstances nearly fifty years ago after his journey in the 
province of Angola. 

Just as cheeses vary in different countries, so curdled 
milk varies slightly according to the nature of the flora 
of microbes. Taking all the soured milks that are pro- 
duced by natural processes, it may be said that the greater 
number of them contain not only microbes that produce 
lactic acid, but also yeasts that cause alcoholic fermenta- 
tions. Kephir, which is prepared from the milk of kine, 
and koumiss, which is a product of mares' milk, are 
notably alcoholic. Koumiss is the well-known national 
beverage of the Kirghises, Tartars and Kulmucks, nomads 


of Asiatic Russia who are famous horse breeders, whilst 
kephir is the native drink of the mountaineers of the 
Caucasus, the Ossetes, and some other tribes. 

It has been supposed that the chief merit of kephir was 
that it was more easy to digest than milk, as some of its 
casein is dissolved in the process of fermentation. Kephir, 
in fact, was supposed to be partly digested milk. This 
view has not been confirmed. Professor Hayem thinks 
that the good effects of kephir are due to the presence of 
lactic acid which replaces the acid of the stomach and 
has an antiseptic effect. The experiments of M. Rovighi, 
which I spoke of in The Nature of Man, have confirmed 
the latter fact, which now may be taken as certain. The 
action of kephir in preventing intestinal putrefaction de- 
pends on the lactic acid bacilli which it contains. 

Kephir, although in some cases certainly beneficial, 
cannot be recommended for the prolonged use necessary if 
intestinal putrefaction is to be overcome. It is produced 
by combined lactic and alcoholic fermentations, and as it 
contains up to one per cent, of alcohol, its use as a food 
for years would involve the absorption of considerable 
quantities of alcohol. The yeasts which produce it can be 
acclimatised in the human digestive tract, in which, how- 
ever, they are harmful, as they are favourable to the germs 
of infectious diseases such as the bacillus of typhoid fever, 
and the vibrio of Asiatic cholera. 

Kephir has also the disadvantage that its flora varies 
considerably and is not well known. There has been little 
success in producing it by pure cultures as would be 
necessary were it to be brought into general use. When 
it is prepared from a dried remnant there is the risk of 
stray microbes being included, and these may bring about 
pernicious fermentations. Professor Hayem prohibits its 


use in the case of persons in whom food is retained for 
long in the stomach. " When it is retained in the stomach, 
kephir goes on fermenting, and there are developed in the 
contents butyric and acetic acids which aggravate the diges- 
tive disturbances." l 

As it is the lactic and not the alcoholic fermentation on 
which the valuable properties of kephir depend, it is 
correct to replace it by soured milk that contains either no 
alcohol or merely the smallest traces of it. 

The fact that so many races make soured milk and use 
it copiously is an excellent testimony to its usefulness. 
M. Nogueira has written to me to say how much he was 
astonished, on revisiting after a long period of absence 
the district of Mossamedes, to find the natives so well pre- 
served and displaying so few traces of senility. Dr. Lima 
has stated that amongst the natives of the region south 
of Angola "many individuals of extraordinary longevity 
are to be found." 1 Although they are thin and withered, 
these old people are very active and can make long 

Mr. Wales, a lawyer at Binghampton, U.S.A., has been 
so good as to make me acquainted with some extremely 
interesting facts taken from a work by James Riley which 
is now a bibliographical rarity. 2 In the narrative of a ship- 
wreck of the vessel on which he made a voyage in 1815, 
James Riley states that the wandering Arabs of the desert 
live almost wholly on the milk of camels, fresh or soured. 

1 Presse mtdicale, 1904, p. 619. 

* "An authentic narrative of the loss of the American brig Commerce 
wrecked on the western coast of Africa in the month of August, 1815, 
with an account of the sufferings of the surviving officers and crew, 
who were enslaved by the wandering Arabs on the African desert or 
Zaharah ; and observations historical, geographical, etc." by James 
Riley. Hartford, S. Andrus and Son, 1854. 


On this diet they enjoy excellent health, display great 
vigour and reach advanced ages. Riley estimated that 
some of the old men must have lived for two to three 
hundred years. No doubt these figures are much too high, 
but it is probable that the Arabs Riley encountered lived 
really unusually long. 

Mr. Wales has examined Riley's work critically, and 
is of the opinion that that author was a well-informed, 
sagacious and conscientious observer. 

M. Grigoroff, a Bulgarian student at Geneva, has been 
surprised by the number of centenarians to be found in 
Bulgaria, a region in which yahourth, a soured milk, is 
the stable food. Some of the centenarians, described by 
M. Chemin in his memoir, lived chiefly on a milk diet. 
Marie Priou, for example, who died in the Haute-Garonne 
in 1838 at the age of 158 years, had lived for the last ten 
years of her life entirely on cheese and goat's milk (op. cit. 
p. 100). Ambroise Jantet, a labourer of Verdun, who died 
in 1751 at the age of in years, "ate nothing but unleav- 
ened bread and drank nothing but skimmed milk " (p. 
! 33) Nicole Marc, who died aged 1 10 years, at the chateau 
of Colemberg (Pas-de-Calais), a hunch-back and cripple, 
" lived only on bread and milk-food. It was only towards 
the end of her life and after much persuasion that she took 
a little wine " (Chemin, p. 139). 

I owe to the kindness of M. Simine, an engineer in 
the Caucasus, the following communication, taken from 
the newspaper Tiflissky Listok, Oct. 8th, 1904. " In the 
village of Sba, in the district of Gori, there is an old Ossete 
woman, Thense Abalva, whose age is supposed to be 
about 1 80 years (?). This woman is still quite capable 
and looks after her household duties and sews. Although 
she is bent, she walks firmly enough. Thense has never 


taken alcoholic liquors. She rises early in the morning, 
and her chief food is barley bread and butter milk, taken 
after the churning of the cream. Butter milk is a liquid 
containing very many lactic microbes. 

Mrs. Jenny Read, an American, has written to me that 
her father, eighty-four years old, " owes his health to the 
curdled milk which he has taken for the last 40 years." 

Curdled milk and the other products of milk to which 
I have referred are the work of the lactic microbes which 
produce lactic acid at the expense of milk sugar. As many 
different kinds of soured milk have been consumed on a 
vast scale and have proved to be useful, it might be 
supposed that any of them is suitable for regular con- 
sumption with the object of preventing intestinal putrefac- 

From the point of view of flavour I find that soured 
milk, prepared from raw milk, is much the more agree- 
able. However, when a food is to be selected for con- 
sumption during a long period of time, we must keep 
hygiene strictly in view. It is certain, therefore, that the 
Russian " prostokwacha, " as well as any other soured 
raw milk, must be rejected. Raw milk contains a large 
assortment of microbes, and frequently some of these are 
harmful. The bacillus of bovine tuberculosis, as well 
as other pernicious microbes, may be found in it. Accord- 
ing to the investigations of Heim l the vibrios of Asiatic 
cholera, when placed in raw milk, survive even when the 
milk has become quite soured. In similar conditions the 
bacillus of typhoid fever remains alive for 35 days and dies 
only after it has been kept for 48 days in completely soured 

1 Arbeiten a. d. k. Gesundheitsamte, 1889, vol. v, pp. 297-304. 


As raw milk nearly always contains traces of faecal 
matter from the cow, it sometimes happens that pernicious 
microbes are introduced from that source, and remain alive 
notwithstanding the acid coagulation of the milk. The 
lactic microbes certainly prevent the multiplication of other 
microbes, as, for instance, those of putrefaction, but are 
incapable of destroying them. Moreover, raw milk often 
contains fungi (yeasts, torulas, and oi'dia) the presence of 
which is favourable to the development of such pernicious 
microbes as the cholera vibrio and the bacillus of typhoid 

Prolonged consumption of raw milk increases the risk 
of introducing dangerous microbes into the organism, and 
this possibility drives me to recommend soured milk pre- 
pared after heating. Theoretically, it would be best to 
sterilise the milk completely so that all the contained 
microbes would be destroyed. This, however, requires 
heating the milk to a temperature of from 226 to 248 
Fahr., by which it acquires an unpleasant flavour. On 
the other hand, the pasteurising of milk at a temperature 
of about 140 Fahr. is not sufficient to get rid entirely of 
the bacilli of tuberculosis and the spores of the butyric 
bacilli. We have, therefore, to fall back on a middle 
course, and be content with boiling the milk for several 
minutes. By so doing we certainly kill the tubercle bacilli 
and the spores of some of the butyric bacilli, 1 there being 
left only some butyric spores and the spores of Bacillus 
subtilis, to destroy which a much higher temperature is 

As some kinds of soured milk, such as " varenetz," 
41 yahourth," " leben," etc., are prepared from boiled milk, 

1 See Grasberger and Schattenfroh, Archii'.fiir Hygiene, 1902, rol 
xlii, p. 246. 


it might be supposed that they fulfil the conditions neces- 
sary for prolonged use. A closer examination, however, 
makes us reject them. 

Boiled milk, to make it undergo the lactic fermentation 
properly, must have added to it a prepared ferment. What 
is necessary is not merely rennet, as was formerly sup- 
posed, but a number of organised ferments, that is to say, 
microbes. In the preparation of these soured milks, a 
leaven is employed, one of the names of which is " Maya,"' 
and which contains not only lactic microbes, but several 
others. MM. Rist and Khoury l have come to the conclu- 
sion that the Egyptian "leben" contained a flora com- 
posed of five species, three of which are bacteria and two 
yeasts. The bacteria produce lactic acid and the yeasts 
alcohol. Although the result is that " leben " is a nearly 
solid substance, whilst kephir is a liquid, the two are closely 
similar. In both cases we have to do witfi coincident lactic 
.and alcoholic fermentations, and my remarks regarding 
kephir apply equally well to the Egyptian " leben." 

Through the agency of Prof. Massol of Geneva, I have 
obtained a specimen of the Bulgarian " yahourth." Work- 
ing with his pupil, M. Grigoroff, M. Massol 2 has isolated 
several microbes from this milk, amongst these being a 
very active lactic bacillus. The same soured milk has been 
studied in my laboratory by Drs. M. Cohendy 3 and 
Michelson. They found in it a very powerful lactic fer- 
ment, which has been named the Bulgarian bacillus. This 
was the microbe employed in the experiments of M. Belon- 
owsky, to which I have already referred. More recently, it 
has been carefully investigated from the chemical point of 

1 Annales de tlnstitut Pasteur, 1902, p. 65. 

- Revue mMicale de la Suisse romande, 1905, p. 716. 

8 Comptes rendus de la Soc. Biologique, March i;th, 1906. 


view by MM. G. Bertrand and Weisweiler l at the Pasteur 
Institute. It proved to be an extremely active producer of 
lactic acid, supplying 25 grammes per litre of milk. The 
other acids which this bacillus produces, such as succinic 
and acetic acids, are formed only in very small quantities 
(about 50 centigrams a litre). Formic acid is produced 
only in traces. On the other hand, the Bulgarian bacillus 
forms neither alcohol nor acetone, two frequent products of 
bacterial fermentation. The bacillus also differs from other 
lactic ferments inasmuch as it has no action on albumin- 
oids (casein, etc.), nor on fats. All these qualities make 
the Bulgarian bacillus much the most useful of the microbes 
which can be acclimatised in the digestive tube for the 
purpose of arresting putrefactions and pernicious fermenta- 
tions, such as the butyric fermentation. 

As in all the known soured milks (yahourth, leben, pro- 
stokwacha, kephir, and koumiss) the lactic bacilli are asso- 
ciated with a rich flora in which pernicious microbes may 
be met (such as the red torula, a microbe which predis- 
poses to cholera and typhoid fever, which I found in the 
leaven of yahourth, bought in Paris), it is necessary to 
work out a method by which good curdled milk can be 
produced with the aid of pure cultures of the lactic microbes. 

It was the obvious course to begin with the Bulgarian 
bacillus, as that is known to be the best producer of lactic 
acid. It coagulates milk rapidly, giving it a strongly acid 
flavour, but it often also gives a disagreeable taste of tallow. 
It is true that after it has been kept for a long time in the 
laboratory in the form of pure cultures in sterilised milk, 
the bacillus loses to a large extent its power of saponifying 
fats, the taste of the curdled milk befng then more agree- 
able. If necessary, therefore, soured milk prepiared exclu- 
1 Annales de PInstitut Pasteur, 1906, p. 977. 

N 2 


sively with the Bulgarian bacillus can be used. -In practice, 
however, it is useful to associate with it another lactic 
microbe, known as the paralactic bacillus, as the latter, 
although producing less lactic acid than the Bulgarian 
bacillus, does not break up the fats and gives the curdled 
milk a very pleasant flavour. 

As it is undesirable to absorb too much fatty matter, it 
is necessary to prepare curdled milk for regular use from 
skimmed milk. After the milk has been boiled and 
rapidly cooled, pure cultures of the lactic microbes are 
sown in it, in sufficient quantities to prevent the germina- 
tion of spores already in the milk and not destroyed in 
the process of boiling. The fermentation lasts a number 
of hours, varying according to the temperature, and finally 
produces a sour curdled milk, pleasant to the taste and 
active in preventing intestinal putrefaction. This milk, 
taken daily in quantities of from 300 to 500 cubic centi- 
metres, controls the action of the intestine, and stimulates 
the kidneys favourably. 1 It can therefore be recommended 
in many cases of disorder of the digestive apparatus, of 
the kidneys, and in several skin diseases. 

The Bulgarian bacillus taken from yahourth or from 
soured milk, prepared from pure cultures of lactic microbes, 
can live in warm temperatures, and, as has been shown 
by Dr. Cohendy, is able to take its place in the intestinal 
flora of man. 

Soured milk, prepared according to the receipt which 
I have given, has been analysed by M. Fouard, an assist- 
ant at the Pasteur Institute. When it was ready to be taken, 
M. Fouard found in it about 10 grammes of lactic acid per 
litre. Moreover, a large proportion (nearly 38 per cent.) 
of the casein had been rendered soluble during the fer- 

1 Soured milk can be taken at any time of the day, with or in between 


mentation, which shows that its albuminous matter is pre- 
pared for digestion much as in kephir. Of the phosphate 
of lime (which is the chief mineral substance of milk) 68 per 
cent, was rendered soluble during the fermentation. These 
facts all confirm the utility of the soured milk prepared 
from pure cultures of lactic bacteria. 

Those persons who, from some reason or other, cannot 
take milk, may swallow the bacilli in a pure culture with- 
out milk. However, as the microbes need sugar to produce 
lactic acid, it is necessary to take with them a certain 
qjuantity of sweet food (jam, sweet-meats, and especially 

The Bulgarian bacillus produces lactic acid not only 
from milk sugar, but also from many other sugars, for in- 
stance, cane sugar, maltose, levuloseand especially glucose. 

Cultures of the bacillus can be made not only in milk, 
but in vegetable broths, or broths of animal peptone to 
which sugar has been added. The cultures can be taken 
in a dry form (powders or tabloids), or in the liquid in 
which the bacilli had themselves been developed. 

A reader who has little knowledge of such matters may 
be surprised by my recommendation to absorb large quan- 
tities of microbes, as the general belief is that microbes 
are all harmful. This belief, however, is erroneous. There 
are many useful microbes, amongst which the lactic bacilli 
have an honourable place. Moreover, the attempt has 
already been made to cure certain diseases by the adminis- 
tration of cultures of bacteria. M. Brudzinsky 1 has used 
cultures of lactic microbes in certain intestinal diseases of 
infants, whilst Dr. Tissier 2 has used them in similar 
affections of infants and adults. 

1 Jahrbuch fur Kindertieilkunde, N. F. 12 Ergansungsheft, 1900. 

2 Annales de tlnstitut Pasteur, 1905, p. 295 ; Tribune medicate, Feb. 
24th, 1906. 


From the general point of view of this book, the course 
recommended consists of the absorption either of soured 
milk prepared by a group of lactic bacteria, or of pure 
cultures of the Bulgarian bacillus, but in each case taking 
at the same time a certain quantity of milk sugar or 

For more than eight years I took, as a regular part 
of my diet, soured milk at first prepared from boiled milk, 
inoculated with a lactic leaven. Since then, I have changed 
the method of preparation and have adopted finally the pure 
cultures which I have been describing. I am very well 
pleased with the result, and I think that my experiment has 
gone on long enough to justify my view. Several of my 
friends, some of whom suffered from maladies of the intes- 
tine or kidneys, have followed my example, and have been 
well satisfied. I think, therefore, that lactic bacteria can 
render a great service in the fight against intestinal putre- 
faction . 

If it be true that our precocious and unhappy old age is 
due to poisoning of the tissues (the greater part of the 
poison coming from the large intestine inhabited by num- 
berless microbes), it is c4ear that agents which arrest intes- 
tinal putrefaction must at the same time postpone and 
ameliorate old age. This theoretical view is confirmed by 
the collection of facts regarding races which live chiefly on 
soured milk, and amongst which great ages are common. 
However, in a question so important, the theory must be 
tested by direct observations. For this purpose the numer- 
ous infirmaries for old people should be taken advantage of, 
and systematic investigations should be made on the rela- 
tion of intestinal microbes to precocious old age, and on 
the influence of diets which prevent intestinal putrefaction 
in prolonging life and maintaining the forces of the body. 
It can onlv be in the future, near or remote, that we shall 


obtain exact information upon what is one of the chief 
problems of humanity. 

In the meantime, those who wish to preserve their intel- 
ligence as long as possible and to make their cycle of life 
as complete and as normal as is possible under present 
conditions, must depend on general sobriety and on habits 
conforming to the rules of rational hygiene. 




Reply to critics who deny the simian origin of man 
Actual existence of rudimentary organs Reductions in the 
structure of the organs of sense in man Atrophy of Jacob- 
son 's organ and of the Harderian gland in the human race 

SEVERAL critics of The Nature of Man have protested 
against my theory of the simian origin of man. Some of 
these found my arguments unsatisfactory and unconvinc- 
ing. Others have attacked generally my suggestion that 
some anthropoid had been suddenly transformed to a 
primitive human being. 

It is true that so long as we have little palaeontolo- 
gical evidence as to the actual descent of man, we cannot 
discuss the subject without the aid of hypotheses. I think, 
however, that recent additions to knowledge confirm the 
theory of the descent of man in a way that ought to influ- 
ence the most resolute opponents. I have in mind chiefly 
the arguments supplied by the embryology of anthropoid 
apes, and by the investigation of their blood. None the 
less, there are still many authors who maintain their oppo- 
sition. One of my critics, Dr. Jousset, 1 enumerates certain 
differences in the structure of the skeleton in man and apes, 
and concludes that these radically separate man from apes. 
1 La nature hitmaine et la philosophic optimiste, Paris, 1904. 


No one has ever doubted that man was not identical in 
structure with the anthropoid apes, or that he differs from 
th^m in several characters of the skeleton and of many 
other organs. The differences, however, do not justify any 
radical separation of the two. The unusual length of arm, 
upon which my opponents throw so much weight, is in 
harmony with the mode of life of apes, as these climb on 
trees and walk on all four limbs. The difference between 
apes and Europeans in length of arm is certainly consider- 
able, but is much less in the case of some lower races, such 
as the Veddahs. In the Akkas of Central Africa, the arms 
are so long that the hands nearly reach the knees. The 
foetus of Europeans also shows an unusual length of arm, 
probably an ancestral feature. It is only after birth that 
the arms become relatively shorter. 

All the other characters different in man and the apes, 
are equally secondary. On the other hand, just as apes 
differ amongst themselves, so also, the different races show 
differences often strongly marked. M. Michaelis, 1 in a 
comparative study of the muscular systems of monkeys, 
has made known many details of the musculature in the 
orang-outan and the chimpanzee, and it appears from his 
investigations that, although there are some differences 
between these two apes, they are both closely similar to man . 

There are many variations in the muscular structure of 
man, and these find parallels in the muscles of apes. This 
is also the case with other abnormalities of structure, some 
of which resemble the condition in mammals much lower 
than apes. An example of this is the presence of addi- 
tional pairs of nipples, arranged symmetrically on the sides 
of the chest and occasionally found in human beings. A 
similar abnormality has been found in some monkeys, and 
1 Archiv.f. Ana/, u. Physiol., Anatom. Abtheil, 1903, p. 205. 


the best explanation of such an occurrence is that monkeys, 
like man, are descended from mammals which possessed 
several pairs of mammary glands. 

The large number of abnormalities and rudimentary 
organs which may be found in man affords important 
evidence in favour of the descent of man from lower 
animals. Some authors, however, have tried to dispute 
this view and even deny the existence of rudimentary 
organs. M. Brettes, 1 amongst my opponents, has brought 
together most facts upon this matter, with the object of 
proving that such organs fulfil some function indispensable 
to the body and bear witness to the existence of a general 
plan of organisation. My opponent, however, confines 
himself to general propositions, laying much stress on a 
law of "the subordination of organs" without proving 
that rudimentary organs have an actual function. In The 
Nature of Man I remarked on the uselessness of the 
wisdom teeth, which are not cut until long after childhood 
and which are useless in mastication. In many human 
beings these teeth never cut through the gum, and their 
absence is no disadvantage. This is a typical case of a 
rudimentary organ. To maintain the contrary it would be 
necessary to prove that the wisdom teeth fulfil an indis- 
pensable function and that their absence was in some way 
harmful to the organ ism. No one has been able to show this. 

The mammary glands in males are another case of rudi- 
mentary organs. The function of these, of course, is well 
known in females, but it is only in the rarest cases that 
they are active in males. 

The organs of sense supply many cases of rudimentary 
structures. Animals which live in caves, in the dark, do 
not discern objects by sight, and in these cases the eyes are 

1 Dunivers et la vie, p. 592. 


rudimentary. It is quite impossible to deny the existence 
of rudimentary organs. They are extremely important 
guides to us in our investigation of the past history of the 
human race. The comparative study of the organs which 
are rudimentary in man and more or less well developed in 
lower animals is of fundamental importance in the problem 
of our origin. 

The higher apes, or anthropoids, display reduction in 
some parts of the organs of sense. The organ of smell, 
for instance, is much less developed in them than in many 
other animals. Man has inherited the imperfect condition 
of this organ, and his sense of smell is much less developed 
than that of mammals which are lower in the scale of life. 
Man, however, because of his intelligence, has been able 
to tame domestic animals, such as dogs, ferrets, and pigs, 
and to make use of their acute sense of smell for tracking 
game or obtaining edible plants. The imperfect condition 
of the sense of smell in man in other cases is well re- 
placed by his mental powers. He no longer recognises the 
approach of an enemy by the sense of smell, in order that 
he may take flight, because he has better means of defence 
than those of animals. It is not surprising, therefore, that 
the olfactory apparatus of man is much reduced as com- 
pared with that of lower mammals. In apes and man the 
nasal region of the head is much smaller than in their 
mammalian ancestors, and in the deep-lying parts of the 
system there are corresponding differences. Most 
mammals, for instance, and the dog in particular, have four 
turbinal bones, the purpose of which is to increase the 
surface of the mucous membrane of the nose, whilst in 
man there are only three, one of which is rudimentary. 

The olfactory apparatus in most mammals contains a 
well-developed portion known as the organ of Jacobson, 


the probable function of which is to appreciate the flavour 
of food in the mouth. In man, this organ is in a rudi- 
mentary condition and cannot fulfil its function, as it is 
devoid of its proper nerve. This remnant, now useless, 
gives us information as to the evolution of the organ of 
smell in man. In the human foetus, Jacobson's organ is 
not only better developed than in adult man, but it is also 
provided with a stout nerve trunk, which disappears to- 
wards the end of embryonic life. The organ, however, 
cannot perform any olfactory function. The human foetus, 
moreover, possesses five turbinals which later on become 
reduced to three, and of these only two develop completely. 

The history of the evolution of the organ of smell, as it 
has been made out by comparative anatomy and embry- 
ology, links this apparatus in man with the corresponding 
organs of other mammals by means of these useless rudi- 
ments, which, however, are important evidence in scien- 
tific theory. 

The auditory apparatus also has become reduced in man. 
Many animals, in the struggle for existence, require a very 
acute sense of hearing, more so than man or some of the 
most intelligent mammals. We have all seen how horses 
raise their ears to hear better when there is the slightest 
sound near them. Monkeys and man have lost this power, 
and man sometimes tries to supply the defect by artificial 
means. When a lecturer, for instance, is not speaking 
sufficiently loud some of the audience put their hands to 
their ears, making a kind of trumpet which serves to catch 
the sound. The human external ear is supplied with 
muscles, but in most cases these are too feeble to move it. 
In very rare cases persons can move their ears, the muscles 
inserted to the shell in most of us being mere rudiments of 
those that existed in our ancestors. 


In the organ of sight, the little fold in the inner angle 
of the eye, known as the semilunar fold, is of special 
interest. This membrane is a useless vestige of a struc- 
ture much better developed in lower mammals. In the 
dog it is present as a small third eyelid, supported by a 
special cartilage provided with a secreting gland, known 
as the Harderian gland. In birds, reptiles and frogs, the 
corresponding structures are much better developed. 
Everyone has seen the delicate membrane which, in the 
case of a bird, may shoot out from the inner angle of the 
eye and cover the whole of the exposed part of the eyeball 
(nictitating membrane). In these animals, the eye is pro- 
tected by this third lid, which has its own muscles. As 
in the dog, this third eyelid of birds and lower vertebrates 
is generally provided with a large Harderian gland, which 
produces a liquid secretion like tears. 

In most monkeys, this apparatus is much reduced. 
Many of them have still a small Harderian gland and a 
weak third eyelid. In man, as I have already said, there 
are only vestiges of these organs, the gland being almost 
atrophied and the third eyelid represented only by an in- 
significant crescentic fold. In the lower races the fold 
sometimes contains a small cartilage. Giacomini found it 
twelve times in sixteen negroes, whilst in 548 white people 
it was found only in three cases. 

The interpretation of these facts is not doubtful. This 
little fold is the last vestige in use of an organ which was 
useful only in our remote ancestors. 

The organs of reproduction in the human race also show 
a number of rudiments. There remain even traces of & 
hermaphrodite condition, a very low degree of organisa- 
tion, going back to extremely remote ancestors. The 
evidence given by the very large number of abnormalities 


that are found fn these organs makes it clear that, in the 
long period of the evolution of the human race, they have 
been subjected to a series of modifications. Thus, for in- 
stance, there is occasionally present in women a form of 
uterus resembling that of the lower mammals, or even the 
double uterus of marsupials. 

The evolution of man has been dominated by the great 
development of the brain and of the intelligence, and man, 
accordingly, has lost many organs and functions which 
were of use in his more or less remote ancestors. 



The mental character of anthropoid apes Their muscular 
strength Their expression of fear-^The awakening of latent 
instincts of man under the influence of fear 

THE facts of which I have given a re'sume' serve to show 
that evolution always leaves definite traces indicating its 
successive stages in the form of rudiments. It is probable, 
therefore, that the pre-human mental functions or psycho- 
physiological qualities, which have so long a history 
behind them, have also left more or less appreciable traces. 
These, however, must be more difficult to find than rudi- 
mentary organs which can be made visible by dissection. 

If we turn first to the animals most nearly related to 
man, we find that the living anthropoid apes show in the 
clearest way their close relationship with the human race, 
and suggest that their kinship with our remoter ancestors 
must be even greater. 

The anthropoid apes alive to-day are animals inhabit- 
ing chiefly virgin forests, and feeding on fruits and shoots, 
although they do not despise eggs or even little birds. To 
satisfy their wants, they climb with the greatest ease,. 
Orang-outans and chimpanzees climb slowly and carefully, 
whilst -gibbons show a greater agility and more perfect 
acrobatic power. They may be seen throwing themselves 


from branch to branch across spaces of forty feet with 
the greatest precision. They play at the top of very tall 
trees, hardly grasping the branches through which they 
pass, making leaps of from twelve to eighteen feet for 
hours together with little apparent exertion. 

To give an idea of the dexterity and swiftness of 
gibbons, Martin took the case of a female which he ob- 
served in captivity. One time she hurled herself from a 
perch across a space at least twelve feet wide, against a win- 
dow which one would have thought would have been 
immediately broken. To the great surprise of the spec- 
tators it was not broken. The gibbon seized with her hands 
the narrow board between the panes, and then in an instant 
twisted herself round and jumped back to the cage she had 
left, performing this manoeuvre with great strength and 
the most marvellous precision. 

The muscular force implied in the above narrative is 
possessed by all the anthropoid apes. Battel, an English 
sailor who gave the first description of the gorilla in the 
beginning of the i7th century, stated that the strength of 
that animal was so great that ten men could hardly master 
an adult specimen. The other anthropoids, although not so 
strong as the gorilla, nevertheless display surprising force. 

Edouard, the young male chimpanzee which I used in 
my experiments on syphilis, struggled so much at the 
least touch that it took four men to master him. I had to 
give up allowing him to leave his cage because there was 
no way of getting him back to it. Even quite young 
chimpanzees, females not yet two years old, cannot be 
handled easily. Although they are very friendly, my 
specimens used to resist with all their strength when it was 
necessary to put them back in their cages for the night. 
Two men had much ado to shut them up. 


Notwithstanding this great muscular force, the anthro- 
poid apes are cowardly. They have no idea of their 
strength, but fly from the approach of the slightest imagined 
danger. My young chimpanzees, although their teeth and 
muscles were already formidable weapons, showed the 
greatest fear when I put with them animals even so weak 
and harmless as guinea-pigs, pigeons and rabbits. Mice 
frightened them very much at first, and it took them a con- 
siderable time before they got over their fear of so insig- 
nificant an enemy. When living in a state of nature the 
anthropoid apes scarcely ever assume the offensive. 
" Though possessed of immense strength," wrote Huxley, 1 
" it is rare for the Orang to attempt to defend itself, espe- 
cially when attacked with fire-arms. On such occasions 
he endeavours to hide himself, or to escape along the top- 
most branches of the trees, breaking off and throwing down 
the boughs as he goes." Savage 2 wrote of chimpanzees 
that "they do not appear ever to act on the offensive, and 
seldom, if ever really, on the defensive." When a female 
was surprised on a tree with her young ones "her first 
impulse was to descend with great rapidity and make off 
into the thicket." 3 

The gorilla, the strongest and most ferocious of the 
apes, has sometimes been observed to take the offensive. 
Savage, quoted by Huxley, said that " they are exceedingly 
ferocious, and always offensive in their habits, never run- 
ning from man, as does the chimpanzee. The females 
and young, at the first cry, quickly disappear. He (the 
male) then approaches the enemy in great fury, pouring 
out his horrid cries in quick succession." 4 Only males" 

1 Huxley, Man's Place in Nature. Collected Essays, vol. vii, p. 54. 

2 Ibid., p. 60. 3 Ibid., p. 62. 4 Ibid., p. 67. 


take the offensive, nor can this be of frequent occurrence, 
as one of the most recent observers, Koppenfels, 1 states 
that "the gorilla never attacks man spontaneously; he 
tries to avoid him, and, as a rule, takes to flight as soon as 
he sees a man, uttering peculiar guttural cries." 

Which of these characters are preserved in the human 
race ? Man is naturally feebler and less of a gymnast than 
the great apes, but his disposition is cowardly. One of 
the earliest signs of mental activity in an infant is the fear 
of surrounding circumstances. The smallest change in its 
balance or its being put in a bath cause it to show signs of 
real terror. Later on, it is alarmed when it sees any kind 
of animal, exactly in the fashion of a young chimpanzee. 
The most harmless spider is enough to frighten it. 

Although mental culture subdues fear to a large extent, 
fear reveals itself more or less strongly from time to time, 
and it is on such occasions that we may find in the human 
being psychological relics of his ancestors. An analysis 
of fear is of special interest. 

The first result of the emotion of fear is flight. Con- 
sciousness of danger sets our limbs in motion, and our 
instinctive desire to escape displays itself even when flight 
is more dangerous than what we wish to avoid. At the 
first alarm of fire in a public building, people rush towards 
the exits and in so doing often perish from their wish to 
escape. Even in the extreme of terror, the desire of flight 
is one of the earliest impulses. Mosso, a well-known 
Italian physiologist, in a monograph on fear, relates that 
when a Calabrian brigand was sentenced to death " he 
uttered a sharp cry, heart-rending and terrible, looked 
around him as if he were eagerly seeking for something, 
and then stepped backwards as if to fly, and threw himself 
1 Mngaux, Les Manmmiferes, p. 24. 


against the wall of the court, writhing, with arms out- 
stretched, scratching at the wall as if he were trying to 
break through it." 

Although in such a case it was futile and often is 
harmful, the instinct of flight from danger is inherited 
from ancestors from a time when it served to save life. 
Attempts to escape are not the only signs of fear. There 
is often a trembling fit which would make flight impos- 
sible. In Mosso's case of the Calabrian brigand, "after 
his struggles, cries and contortions, he fell on the ground 
in a motionless heap, like a wet rag ; he became pale and 
trembled more than I have seen any other person tremble ; 
his muscles seemed changed into a soft and quivering 
jelly." This condition of trembling inertia is another 
legacy from animals. Quivering of the muscles often 
manifests itself in terrified animals. Darwin 1 wrote of it, 
"trembling is of no service, often of much disservice, 
and cannot at first have been acquired through the will, 
and then rendered habitual in association with any 
emotion." The phenomenon seemed to him obscure and 
difficult to explain, a view shared by Mosso. The trem- 
bling of the musculature of the body is a generalised and 
exaggerated form of the movements of the cutaneous 
muscles in the condition known popularly as "goose- 
skin." The latter, however, is a relic of an adaptation 
useful to some animals. The hedgehog rarely takes to 
flight at the approach of danger, but stands still, and using 
strongly developed muscles, rolls itself into a ball. In 
birds and many mammals, the muscles of the skin cause 
erection of the feathers or hairs. These movements often 
are performed during fright, and according to Darwin, 

1 Darwin, Expression of the Emotions in Man and Animals, 1873, 
p. 67. 

O 2 


serve not only to warm the skin, but sometimes to make 
the animal appear larger and more terrifying to enemies. 

Fear and cold alike cause contraction of the superficial 
blood-vessels, and, in man, excite the contraction of the 
minute rudimentary muscles inserted to the roots of the 
hairs. " Goose-skin " is caused by the contraction of these 
muscles, the condition being a functional rudiment, no 
longer serving to warm the skin nor to make the body 
appear larger. In a few exceptional cases, "goose-skin" 
can be produced voluntarily. In the normal condition, 
the rudimentary cutaneous muscles of man are immobile, 
and it requires some special stimulation to set them in 

Fear, which is occasionally able to excite the contrac- 
tion of the involuntary muscles, also stimulates other 
muscles against the will. Under the influence of emotions 
that powerfully affect the nervous system, and particularly 
under that of fear, contractions of the bladder and intes- 
tines may be so violent that it is impossible to prevent the 
voiding of their conte'nts. Accidents of this kind are not 
infrequent in the case of youthful candidates at examina- 
tions. Mosso relates of a friend, a volunteer in the war 
of 1866, that he was seized with terror during a battle and 
that the utmost efforts of his will failed to make his body 
endure the terrible spectacle. 

The involuntary action of the bladder and intestines 
during fear is a legacy from animals. The phenomenon is 
common in dogs and monkeys. Chimpanzees, when laid 
hold of, discharge their urine and faeces. At Madeira I 
had an unusually cowardly Cercopithecus monkey which 
when at all alarmed discharged the contents of the rectum. 
Quite possibly such a mechanism was useful for the pre- 
servation of the individual. The emission of various kinds 
of excretions is of use in the struggle for existence. In 


that way the fox drives the badger from its earth and takes 
possession of it, whilst polecats and skunks defend them- 
selves against more powerful carnivorous animals by dis- 
charging on them foetid secretions. 

Instinctive fear is therefore a very powerful stimulant, 
awakening functions which are rudimentary and almost 
completely extinct. Sometimes it sets in operation 
mechanisms which have long been paralysed. Pausanias 
gives an example of a dumb young man who recovered 
his speech when he was terrified by seeing a lion. Hero- 
dotus relates that the son of Crcesus, who was dumb, on 
seeing a Persian about to kill his father, cried out : " You 
must not kill Crcesus," and from that time onwards was 
able to talk. These ancient narratives have been con- 
firmed by many modern observations. A woman, for 
instance, who had been dumb for several years, on seeing 
a fire, was terrified and cried out suddenly " Fire ! " after 
which her speech was restored. Such are cases of the 
awakening of a function which has been arrested only 
for several years. But fear can bring into activity other 
mechanisms which have been inactive from time im- 

Many different kinds of animals can swim instinctively. 
This is true in the case of most birds and mammals. 
There are some species which show a repugnance to water, 
but none the less swim well enough if they are thrown 
into it. Cats shun water as much as possible, but, none the 
less, can swim quite easily. Historians relate that Han- 
nibal had great difficulty in getting his elephants to cross 
the Rhone. Some females were ferried across first, upon ' 
which the other elephants threw themselves into the water 
to pursue them and swam across the river without any 
difficulty (Lentheric, Le Rhone, 1892, p. 81). 

The lower monkeys can swim without being taught, but 


the anthropoid apes have lost this power, and man also is 
without it. M. Volz 1 states that the different species of 
gibbons which live in Sumatra are separated by rivers. 
Their inability to swim makes these a complete barrier. 
It is probable that the lower races, in this respect, are 
better endowed than we are. It is said that in the case of 
negroes, children run to the sea or to rivers almost as soon 
as they leave the cradle, and learn to swim almost as 
quickly as to walk. 2 In the case of white people, many 
find it very difficult to learn to swim, and it is at least 
certain that swimming is not instinctive as in the case of 
our animal ancestors. Christmann, 3 the author of a treatise 
on swimming, states that the reason of man is a worse 
guide than the infallible instinct of the animal. Fear is 
able to stifle reason and to allow the instinct to come into 
play. It is known that children or adults may be taught to 
swim by throwing them into the water. Under the influence 
of fear, the instinctive mechanism inherited from animals 
aw r akens, and man soon becomes a swimmer. There are 
some teachers of swimming who use this method success- 
fully. I have myself known an individual who learnt the 
art in that way, and M. Troubat, librarian at the Inter- 
national Library, has informed me that one of his friends, 
a journalist who died at Noyon several years ago, bathed 
in the Seine one evening at Neuilly when he could not swim. 
Unexpectedly finding himself beyond his depth, a sudden 
movement of fear saved him. Since then, he said, he 
knew how to swim. 
Just as there are cases in which terror provokes flight, 

1 Biologisckes Centralblatt, 1904, p. 475. 

2 J. de Fontenelle, Nouveau manuel complet des nageurs, Paris, 1837, 
p. 2. 

3 La natation et les bains, Paris, 1887. 


and others in which it causes an arrest of motion, so also 
fear may do a disservice to a swimmer. Those who 
employ fear as a means of teaching to swim, know that 
they must intervene if there is real danger. It is true, none 
the less, that up to a certain point fear can awaken func- 
tions which have been atrophied for numberless genera- 
tions, and that we can learn from it something as to the 
evolution of the human race. 



Fear as the primary cause of hysteria Natural somnam- 
bulism Doubling of personality Some examples of som- 
nambulists Analogy between somnambulism and the life 
of anthropoid apes The psychology of crowds Importance 
of the investigation of hysteria for the problem of the origin 
of man 

THE study of fear is interesting in other respects than those 
with which I have been dealing. It is also a primary cause 
of the obscure and complicated phenomena of hysteria. 

Thus, for instance, amongst twenty-two hysterical women 
observed by Georget 1 the primary causes were : terror, 13 
cases ; extreme grief, 7 cases ; extreme annoyance, one case. 
A patient of M. Pitres, of Bordeaux, first exhibited hysteria 
after being extremely terrified. A man with a tame bear 
had come to the village. The patient went to see the per- 
formance and elbowed her way through the crowd until 
she got to the front row. The bear, whilst dancing, passed 
so close that its cold muzzle touched the cheek of the young 
girl. Marie for that was the patient's name was terri- 
fied. She ran quickly home, and almost on her arrival 
fell on her bed in an attack of convulsion and extreme 
delirium. Since then the attacks have been repeated many 
times, and the delirium associated with them always turns 
upon Ihe terror caused by the bear touching her. 

1 Quoted by M. Pitres in Lffons diniqites sur FhystMe, 1891, vol. i. 


A hysterical woman at the Salpe'triere is haunted by 
terrifying dreams. She thinks someone is trying to murder 
her, or to cut her throat, or that she is falling into water, 
and she keeps crying for help. 1 

Some of the most curious phases of hysteria are the para- 
doxical and extraordinary cases of so-called natural som- 
nambulism, in which the patients, whilst asleep, perform 
all sorts of acts of which they remember nothing in their 
waking hours. Cases of duplication of personality are 
also known, in which the patients live in two different 
states without, in one of these, having the slightest remem- 
brance of what takes place in the other. One of the most 
curious observations was that of the somnambulist who 
became enceinte whilst in her second state. In her first, 
or normal condition, she was ignorant of the reason of her 
physical changes, although in the second state she knew 
about it quite well and spoke freely of it (Pitres, .op. cit. II, 


In the state of natural somnambulism the patients gene- 
rally reproduce the normal acts of their daily life which 
they have acquired the habit of performing unconsciously. 
Artisans devote themselves to their manual work, semp- 
stresses begin to sew, maid servants brush shoes or clothes, 
lay the table and so forth. Educated persons devote them- 
selves to intellectual work to which they are accustomed. 
Clergymen have been known to compose their sermons in 
the somnambulistic condition, and to read them over to 
correct mistakes in style or in spelling. 

However, besides somnambulists who during slumber 
simply repeat the usual acts of their life, there are others 
who do special things to which they are unaccustomed. 

1 Bourneville et Regnard, Iconographie photographique de la Sal- 
pttriere, 1879-1880, vol. iii, p. 50. 


It is these cases which are most interesting from my point 
of view. I shall take one case which has been specially 
well reported. A hysterical patient, a girl of 24 years of 
age, was admitted as an in-patient to the hospital Laennec. 
One Sunday, she got up about one o'clock in the morning. 
The night watchman, who was alarmed, went for the night 
doctor, who witnessed the following scene. "The patient 
went to the staircase leading to the nurses' quarters, then 
suddenly turned round and walked towards the wash- 
house. The door of that being closed, she then groped 
for a time and turned towards the women's dormitory in 
which she had formerly slept. She went up to the top of 
the house where this dormitory was, and when she got on 
the landing, opened a window leading to the roof, went 
out of the window, walked along the gutter, under the 
horrified eyes of the nurse who followed her and who did 
not dare to speak to her, went in again by another window 
and went down the stairs." " It was at this moment that 
I saw her," said the night doctor; " she was walking noise- 
lessly, her gait was automatic, her arms hanging by her 
sides, a little bent, the head erect and fixed, her hair 
disordered, her eyes wide open; she seemed like some 
strange apparition." 1 This is obviously the case of 
a hysterical subject, who in a normal condition was 
not accustomed to climb upon roofs and walk along the 

Another observation, reported by Charcot, related to a 
young man, seventeen years old, the son of a large manu- 
facturer, and of good address. Tired out by working for 
his final examination, he had gone to bed early. Some 
time later he rose from the bed in his college dormitory, 

1 Stephanie Feinkind, Du somnambulisme dit naturel, Paris, 1893, 


went out by a window, and without accident climbed on 
the roof and took a long and dangerous walk along the 
gutters. He was awakened before any accident occurred 
(Feinkind, p. 70). 

A case observed by Dr. Mesnet and M. Mottet was still 
more interesting. A lady thirty years old and extremely 
hysterical got out of bed in the night, "dressed herself, 
completed her toilet without help, removed the furniture 
in her way without stumbling against it. She was in- 
different and idle by day, but strenuous at night in perform- 
ing the most varied acts. I have seen her walking about 
in her rooms, opening doors, going down to the garden, 
leaping on seats with the utmost agility, running about, 
in fact doing all these things much better than in her 
waking hours, in which she got about only slowly and with 
aid" (Feinkind, p. 84). 

Horst has related an extraordinary incident which took 
place in the sixteenth century. "A soldier walked in his 
sleep to a window, and with the help of a rope climbed a 
high tower, secured a jackdaw's nest with its young birds, 
and regained his bed, where he remained asleep until the 
morning." 1 Unfortunately there are not sufficiently de- 
tailed facts regarding this incident, and for fully described 
cases we must return to modern times. Dr. Guinon has 
related one case in ample detail. A man thirty-four years of 
age, by occupation an interpreter, was taken into hospital 
for hysterical attacks. " One night soon after he came under 
the care of the physicians, this patient, towards one o'clock 
in the morning, suddenly arose from bed, threw open a 
window and jumped across the sill into the courtyard of 
the hospital. The attendants on duty ran after him, and 
saw him hurrying away, undressed and carrying a pillow 
1 Dictionnaire des sciences medicates, 1821, vol. lii, p. 119. 


in his arms. He traversed a series of gardens and walks, 
with the topography of which he was unacquainted, climbed 
a ladder and got on the roof of the hydrotherapeutic estab- 
lishment, up and down which he proceeded to run with the 
greatest agility. Sometimes he stopped in his flight and 
rocked the pillow he was carrying, kissing and soothing it 
as if it were a child. Then he retraced the route he had 
taken." On being questioned next morning, he had not 
the faintest remembrance of his nocturnal exploit. "A 
similar fit came on him five or six times "(Feinkind, p. 108). 

The same patient, "after having turned over in bed 
several times, seized a pillow and held it to his breast. He 
then got out of bed, and, in his nightgown, ran through the 
dormitory to a door leading to the lavatories. He opened 
the door, readily but with violence, and entered one of the 
closets. Then, still holding the pillow against his chest 
with one arm, by a gymnastic feat both difficult and dan- 
gerous, yet which he performed with the utmost precision, 
using his feet and the free arm, he got hold of the edge of 
the frame of an open window, through which he swung 
himself to the sill, alighting on both feet, after which, 
preserving the pillow carefully from contact or shocks, he 
jumped to the ground (the infirmary ward was on 
the ground floor). He then ran quickly to the opposite 
corner of the courtyard, passing the whole length of the 
great building at full speed, holding the pillow carefully. 
By a path which led round the building, he reached a 
corner where there was a tower supporting a great water- 
tank. A kind of metallic ladder, placed almost vertically 
and with rounded steps, led up the side of the tower to 
a sort of observation-landing which at one point was adja- 
cent to the edge of the roof of the bath-house. 

" The patient set himself to climb this ladder without any 


hesitation, holding on by his free hand and placing his 
naked feet on the rounded steps with extreme precision. 
When he reached the nearest point to the roof of the bath- 
house he leapt upon that, and at a running pace climbed 
the zinc roof to the crest, looking round him from time 
to time to see if his imaginary pursuers were near. He 
ran along the crest which was so narrow that his feet 
had to be placed alternately on either side on the slopes 
of the steep-pitched roof, a performance so dangerous that 
none of the officials would follow him, and which none the 
less he performed with complete assurance and without a 
single slip. 

' ' When he reached the middle of the building he sat down 
on .the crest of the roof, leaning against a ventilating 
chimney. He then took the pillow which he had been 
carrying carefully, placed it on his knees with a corner 
against his shoulder, and began to rock it as if it were a 
child, crooning to it, stroking it with his hand or with his 
cheek that he pressed gently against the corner. From 
time to time his eyebrows contracted and his looks hard- 
ened, and he gazed around him as if he were being pursued 
or watched, then gave a growl of rage, and took to flight 
again, carrying the pillow on his dangerous path. All the 
time he kept speaking, but we could not hear what he 
said. He saw nothing that was not in his dream; he did 
not understand when his name was called aloud; but he 
could hear, for at the slightest sound near him he rushed 
off again as if his pursuers were upon him. This episode 
lasted about two hours, during which he had climbed over 
all the roofs in the vicinity, defying our pursuit of him ",. 
(Feinkind, pp. 106-112). 

I could give other similar cases, but I think that I have 
shown sufficiently that man, when in the condition of 


natural somnambulism, exhibits qualities that he does not 
possess in the normal state, becoming strong, adroit, and 
a good gymnast, like his anthropoid ancestors. The close 
resemblance between the manoeuvres of Martin's gibbon, 
which I described earlier in this chapter, and the dangerous 
exploits of some sleep walkers is most striking. 

The impulses to climb on roofs and poles, to run along 
in rain gutters, to climb a tower to take a bird's nest, are 
characteristic examples of the instinctive actions of climb- 
ing animals, like the anthropoid apes. Dr. Earth l defines 
somnambulism as " a dream with exaltation of the memory 
and automatic action of the nervous centres, without volun- 
tary and conscious control." "The striking exaltation of 
the memory is the dominating condition. The extreme 
exactness of the memory of places displayed by the som- 
nambulist makes us understand how he performs his noc- 
turnal wanderings, doing almost without the aid of his 
senses numberless deeds of which he would be practically 
incapable in a waking condition." However, as such a 
patient performs new acts which he has never accom- 
plished before in his own individual life, we must suppose 
that the exaltation of memory includes extremely ancient 
facts, dating perhaps from the pre-human period. Man has 
inherited from his ancestors a number of mechanisms of 
the brain, the activity of which is inhibited by restraints 
which have been developed later. Just as man possesses 
mammary glands which under ordinary conditions cannot 
secrete milk, so also, in his brain, there are contained 
groups of cells which are inactive in the normal condition, 
but, also, just as in some exceptional cases man and the 
males of several species of mammals are able to give milk, 
so also in abnormal conditions the atrophied mechanisms 
of other nervous centres begin to act. 

1 Du Sommeil non nature I, Paris, 1886. 


The secretion of milk by males is a return to an extremely 
ancient condition in which both sexes were able to nourish 
the young ; so, also, the gymnastic feats and the extraor- 
dinary strength of somnambulists are a return to a normal 
condition much less remote from us than lactation in males. 

It is curious to find that, in some cases, natural som- 
nambulism is associated with power to move the shell of 
the ear. I know two brothers, who, when they were young, 
used to walk in their sleep in the most typical way. One 
of them, a chemist, used to climb on a high cupboard, or 
simply walk about in the room. The other brother, a 
sailor, in a fit of somnambulism, climbed to the top mast 
of a sailing ship. These brothers, who were somnambu- 
lists, had the cutaneous muscles extremely well developed 
and were able to move their ears voluntarily. 

In this case the abnormality was hereditary in the family, 
and the two daughters of one of the brothers were also 
somnambulistic and had control over the muscles of the 
ears. Here, then, is a case of the simultaneous recurrence 
of two characters of our ancestors : mobility of the ear and 
agility in gymnastic feats. M. Barth characterises the 
somnambulist as "a living automaton in whom conscious 
will is for the time being destroyed." According to him, 
the somnambulist "acts at the suggestion of circum- 
stances, and what seem most extraordinary in what he does 
are in reality instinctive reactions." This description 
agrees well with my view that in natural somnambulism 
the instincts of our pre-human ancestors are awakened, in- 
stincts which under normal conditions are latent and rudi- 

Sometimes, under the stimulus of fear, the instinctive 
mechanism of swimming is awakened in man. It would be 
extremely interesting to know if a similar occurrence took 
place in somnambulists. I have been unable to find in 


literature any sufficient facts upon this subject. I can 
quote only one case, and that with all reserve, which was 
published in the article " Somnambulism " in the Diction- 
naire des Sciences Medicales. "It is related that a som- 
nambulist who took to swimming during one of his fits 
was called by his name several times, and became so 
frightened when he awoke that he was drowned." It 
would be extremely interesting to collect more numerous 
facts on the instincts shown by somnambulists. 

I have given a good deal of attention to natural som- 
nambulism with the idea that I should find in it traits 
recalling those of the life of anthropoid apes. I think that 
the extremely varied phenomena of hysteria could supply 
us with other facts, useful in investigating the psycho- 
physiological history of man. Perhaps some of the facts 
of so-called "lucidity" which are well established could 
be explained as the awakening of special sensations atro- 
phied in the human race, but present in animals. It is 
known that in vertebrate anatomy organs are found which 
have the structures of organs of sense, but which are 
absent or quite rudimentary in the human body. On the 
other hand, it is known that animals perceive some pheno- 
mena of the surrounding world, for the perception of which 
man has no organs of sense. Fish, for instance, appreciate 
gradations in the depth of water, birds and mammals have 
a sense of orientation and can anticipate changes in the 
weather more exactly than our meteorological science. 
When under the influence of hysteria, man may possibly 
be able to recover these senses of our remote ancestors, 
and to know things of which he is ignorant in the normal 

Hysteria is common to man and animals. Amongst the 
numerous chimpanzees which I have owned, several have 
shown signs of hysteria. Some, when they were in the 


slightest degree annoyed, lay on the ground, screaming 
terribly, and rolling about like children in a fit of passion. 
One young chimpanzee used to pull out its hair when it 
was in a fit of temper. The view that hysteria is a relapse 
to the condition of our animal ancestors is supported by 
the conception of hysterical phenomena, suggested by Dr. 
Babinsky. 1 This well-known neurologist thinks that "the 
phenomena of hysteria have two special characters, the one 
being that they can be reproduced by suggestion in some 
cases with the most complete fidelity, and the other that 
they can disappear under the sole influence of persuasion." 
M. Babinsky thinks that "the hysteric patient is neither 
unconscious nor completely conscious, but is in a state of 
special consciousness." In my opinion the latter con- 
dition corresponds to the state of mind of our more or 
less remote ancestors. 

Occasionally a man, under some sudden impulse, falls 
into a condition of extreme violence, and, being unable to 
control himself, commits acts of which he repents imme- 
diately afterwards. It is the custom to say that at such 
times the brute has awakened in the man. This is more 
than a metaphor. CProbably some nervous mechanism 
from a remote ancestor has come into action, at the call 
of some stimulation.) As our anthropoid ancestors and 
primitive man lived in tribes, it is natural that when men 
are grouped together, certain savage instincts should 
awaken. In this connection it is interesting to study the 
psychology of crowds. When man is surrounded by a 
great many of his fellows, he becomes particularly respon- 
sive to suggestion. This condition is* characterised as 
follows by M. G. Le Bon, 2 the author of a study on the 

1 Conference faite d la Socittt de PInternat, June 28th, 1906. 

2 The Crowd: a Study of the Popular Mind. English translation, 
London, 1896. 



psychology of crowds : " The most careful observations 
seem to prove that an individual immerged for some length 
of time in a crowd in action soon finds himself either in 
consequence of the magnetic influence given out by the 
crowd, or from some other cause of which we are ignorant 
in a special state, which much resembles the state of 
fascination in which the hypnotised individual finds him- 
self in the hands of the hypnotiser. The activity of the 
brain being paralysed in the case of the hypnotised subject, 
the latter becomes the slave of all the unconscious activi- 
ties of his spinal cord, which the hypnotiser directs at will. 
The conscious personality has entirely vanished ; will and 
discernment are lost. All feelings and thoughts are bent 
in the direction determined by the hypnotiser" (p. 11). 
Man, under the influence of the crowd, gets into a condi- 
tion like that of a hysterical patient and displays a state of 
mind identical with that of our ancestors. "Moreover, by 
the mere fact that he forms part of an organised crowd, a 
man descends several rungs in the ladder of civilisation. 
Isolated, he may be a cultivated individual ; in a crowd, he 
is a barbarian that is, a creature acting by instinct" 

(P- 13). 

It is quite natural to find relics of our prehistoric past 
in all kinds of hysterical phenomena. We could reach 
extremely interesting facts regarding the tribal and sexual 
life of apes, if we tried to compare with them the pheno- 
mena of human hysteria. The. passionate gestures which 
are characteristic of some hysterical cases could probably 
be explained in this way quite simply, and the wild cries 
uttered by patienfe in acute hysteria would be similarly 

I think that just as anatomists seek for points of com- 
parison between man and animals, as palaeontologists make 


excavations to discover the buried remains of creatures 
intermediate between man and apes, so also, psychologists 
and doctors should investigate the rudimentary psycho- 
physical functions with the object of building up the history 
of the evolution of our psychical life. It cannot be doubted 
that in this branch of science new arguments would be 
found to support the already well founded theory of the 
simian origin of the human race. 

P 2 





Problem of the species in the human race Loss of indivi- 
duality in the associations of lower animals Myxomycetes 
and Siphonophora Individuality in Ascidians Progress 
in the development of the individual living in a society 

IN the following pages I shall try to reply to the criticism 
on The Nature of Man that in that book I only considered 
the individual without thinking of the interests of 
society or of the race. I have been reproached for having 
lost sight of the truth that in the general course of evolu- 
tion the interests of the individual must yield to the higher 
interests of the community. It was asserted, in fact, that 
by advising orthobiosis, that is to say, the most complete 
cycle of human life, ending in extreme old age, I was 
suggesting something to the detriment of humanity as a 

This objection rests on a misunderstanding which it will 
be interesting to clear up. I think that the complete 
development of the individual not only would not injure the 
community but would be of great advantage to it. More- 
over, we must not lose sight of the fact that the individual 
has rights which must not be ignored. 


In the attack on my theory many facts were brought 
forward which show that in the animal and vegetable 
kingdoms the individual is always sacrificed to the advan- 
tage of the race. There is no doubt as to this, and in the 
course of this book I have given exact facts bearing on it. 
I instanced plants such as the Agave and some Crypto- 
gams which die as soon as they have reproduced; I have 
also spoken of the small female round worms (Nematodd) 
which are brutally torn in pieces and devoured by their 
progeny. It would be difficult to find better cases of the 
sacrifice of the individual to the species. The rule, how- 
ever, does not apply to man, who, in this respect, stands 
in a special position. 

Since the arrival of man, several species of animals have 
disappeared from the earth. Man has played a large part 
in the destruction of the Moa (Aepyornis) of Madagascar, 
the largest member of the class of birds. He destroyed 
the Dodo of the Island of Mauritius and Steller's sea cow 
(Rhytina stelleri), a harmless relative of the Manatee, from 
the shores of the Aleutian Archipelago. Man is about 
to cause the extinction of several species of harmful carni- 
vorous animals, such as the wolf and the bear, and possibly 
it will not be long before automobiles have replaced the 
horse, which would then become extremely rare. How- 
ever, although he has destroyed so many other species, 
man has taken good care of himself. The progress already 
made by civilisation has considerably reduced our mor- 
tality. Every year, a large number of young infants are 
kept alive by the aid of hygiene and medicine. The de- 
crease of war and of assassination has also played a part 
in maintaining the race. The position which man has 
acquired in the world makes it more likely that what we 
have to fear is too great an increase of population, and 


although the theory of Malthus has not been verified in 
all its details, it is still true that man could multiply on 
the face of the earth too abundantly. It is already clear 
that almost in the proportion that humanity stops the 
effusion of its blood in war, it tends to limit the propaga- 
tion of the race. 

As the future of the species seems to be safe, it is natural 
to consider in the first place that of the individual. In this 
respect the facts of general biology are of special interest. 

Man is not the only social animal on the earth. Long 
before his appearance other living beings existed in or- 
ganised societies. The splendid colonies of Siphonophora 
float on the surface of the seas, whilst in the ocean depths 
there are societies of corals of extraordinary variability, 
whilst again, on land, many kinds of insects live in highly 
organised societies. 

This social life has been developed without external 
assistance, and without any code to regulate the conduct 
of the individuals united for a common purpose. 

It will be interesting to give a slight survey of the funda- 
mental principles of such societies ; I intend to draw special 
attention to one of the essential points in the societies 
of animals, hoping to elucidate the relations between the 
individuals and society. 

In the organisation of human society the most difficult 
points are the extent to which the society may encroach on 
the individual and the degree to which the individual may 
preserve his rights and his independence. Disputes on 
these have been interminable, and I do not propose to 
discuss the theories according to which an individual must 
be sacrificed for the good of the community to which he 
belongs. I shall limit myself to reviewing the fate of the 
individuals in societies of beings much inferior to man. 


There are examples of societies composed of many in- 
dividuals, even amongst living things on the borderland 
between the animal and vegetable kingdoms. 

There may be found in woods, on dead leaves or on 
decaying timber, minute plants resembling tiny mush- 
rooms. These are Myxomycetes, and the visible portions 
are minute sacs filled with microscopical rounded bodies, 
known as spores. When one of the spores is moistened, 
there emerges a minute organism with a mobile appendage 

FIG. 21. Isolated individuals 
of a Myxomycete. 

(After Zopff.) 

a, spore ; b /, escape of the 

Fio. 22. Myxomycete indi- 
viduals united to form a plas- 

(After Zopff.) 

by which it can be impelled through water. A drop of 
water on a leaf or on a fragment of timber may be filled 
with numbers of these tiny swimming bodies (Fig. 21). 
Their free life as individuals, however, is of brief duration. 
When they come into contact, their bodies fuse, forming 
a gelatinous mass which may be quite large (Fig. 22), 
This mass is called a plasmodium, and is composed of a 
living substance which can move slowly over leaves and 
which exhibits streaming movements in the interior, so 


that the whole resembles in some respects the lava from a 

The plasmodia may be regarded as societies in the con- 
stitution of which the individuality of the members has 
been completely sacrificed. The ideal of those philoso- 
phers who have urged that man should renounce his indi- 
viduality and merge himself in the community has been 
realised in the fullest way at the lower end of the scale 
of life, at an epoch inconceivably remote from the appear- 
ance of the human race. 

Amongst animals, even the most lowly, there are no 
societies in which the members are sacrificed so completely 
to the whole. Individuality is always preserved to a 
greater or lesser extent. Consider the polyps, colonies of 
which form reefs in the sea and may even become 
islands. These creatures live in aggregations, the mem- 
bers of which are incapable of living an independent 
life. They are united by living substance and resemble 
double monsters, such as Doodica and Radica, who were 
so much talked of some years ago when M. Doyen oper- 
ated upon them. The peritoneal cavities of these twins 
were in free communication, and the blood-vessels were 
united so that the blood of the one passed freely into the 
body of the other. In another double monster, the two 
Tscheck girls, Rosa and Josepha, the intestinal tracts 
communicate, both leading to a common rectum. In 
these, who are still alive, the peritoneum is joined and 
there is a single urethra. 

In the case of the coral polyps, the fusion of the indivi- 
duals of the colony is nearly always much more complete. 
Each individual has its own mouth and stomach, whilst the 
other organs cannot be assigned to individuals but must 
be regarded as common to the whole. 


In the swimming polyps or Siphonophora, the loss of 
individuality is still more remarkable. These graceful and 
transparent creatures, sometimes large in size, live in the 
sea and may appear on its surface in great numbers. They 
possess many whip-like filaments provided with tentacles, 
swimming bells and stomachs. There can be no doubt as 
to their colonial nature (Fig. 23), but it is difficult to 
decide as to whether each piece of the 
colony, each swimming bell, stomach 
and so forth, is to be regarded as an 
individual or an organ, different zoo- 
logists having taken different views 
on the question. One interpretation 
is that colonial life has brought with 
it such modifications that of each in- 
dividual there remains only a single 
organ. Some individuals have been 
reduced to simple stomachs, attached 
to the central stem, whilst others have 
lost all organs except that of locomo- 
tion which has become one of the 
swimming bells of the colony. Other 
zoologists, and I myself amongst them, 
think that the Siphonophora are 
colonies of organs in which there has 
been as yet practically no development of individuality. 
A living chain of Siphonophora is simply a number of 
organs such as stomachs, tentacles, swimming bells and so 
forth, united on a common stem. I need not discuss the 
disputed point further, for the only matter pertinent to rrty 
argument is that in the Siphonophora the loss of individu- 
ality, the sacrifice of the parts to the whole, is not so great 
as in the Myxomycetes. 

FIG. 23. One of the 

(After Chun.) 
pn, pneumatic chamber ; 
clh, swimming bells; 
stl, stolon. 



In support of my view, I must recall the small forms of 
Siphonophora known as Eudoxia. These are detached 
pieces of the common trunk which swim freely in the 
sea and have a remarkable structure (Fig. 24). Their 
mobility is due to a bell provided with strong muscular 
fibres. The bell is a portion of an individual which pos- 
sesses organs of reproduction but which is devoid of the 
means to capture or digest food. These two functions 
are performed by a second individual which is closely 
united with the first. The nutrient individual has a long 

FIG. 24. Eudoxia. 
(After Chun.) 

FlG. 25. Botryllus 


o, mouth ; A, common 

tentacle by which the prey is captured, and a capacious 
stomach in which it is digested. The products of diges- 
tion pass by channels into the reproductive individual, 
carrying as it were a ready-made blood. Eudoxia in fact 
is a double being composed of an individual incapable of 
locomotion or of reproduction, but adapted for prehension 
and digestion, and of a second individual which can repro- 
duce and which is mobile. Eudoxia is an association 
resembling that of the blind man and the paralytic, in 
Florian's fable. 

Advance in the organisation of social animals is plainly 


incompatible with complete loss of individuality, and this 
becomes the more apparent the higher we reach in the scale 
of life. In the social Ascidians, each member retains all 
the organs necessary to life. Animals of the genus Botryllus 
(Fig. 25), perhaps the most interesting of these Ascidians, 
occur in the form of circular colonies. The individuals 
which compose the colony are grouped radially around a 
common centre which is occupied by the cloaca. Each in- 
dividual has its own mouth and digestive tube, but the 
latter opens into a cloaca, common to all the individuals, 
by which the excreta are voided. There is, in fact, a single 
anus, as in the case of Rosa and Josepha which I have just 



Social life of insect*? Development and preservation of 
individuality in colonies of insects Division of labour and 
sacrifice of individuality in some insects 

HITHERTO I have dealt with associations of animals the 
members of which are linked by an actual material bond. 
In the insect world there are many cases of highly devel- 
oped colonies. But the organisation of insects is high, and 
is incompatible with the existence of actual physical con- 
nection between the members of the society. 

In early stages of the development of the social instinct in 
bees, fully formed and similar individuals join together 
with the object of securing the safety of their individual 
lives. Sometimes they act together to drive away a 
common enemy, sometimes, as in winter, they cling in a 
mass to maintain their temperature. In such primitive 
societies, the young are not reared in common. It is only 
in much more highly developed colonies, such as those of 
some bees and wasps, and of ants and termites, that the 
chief object of the common action is care of the progeny. 
Such an extreme development of the colony is attained only 
by sacrificing the individuality of the members. There is 
a far-reaching division of labour, so that the queens, for 
instance, are mere machines for laying eggs. In hive-bees 


the queen can no longer judge of what is good for the 
colony, her intellectual functions being degenerate. She 
is enclosed in her cell and supported by the workers, who 
see in her the future of the race. In times of want the 
worker-bees sacrifice their own lives and give the queen the 
last remnants of the food-supply so that she survives them. 
The males are incomplete individuals and are tolerated only 
so long as they are required, after which the workers kill 
them remorselessly. 

The workers, which take such pains for the well-being of 
the hive, are incomplete individuals. Their brains are well 
developed and they are well equipped with organs for 
making wax and collecting food, but their reproductive 
organs are reduced to mere vestiges incapable of fulfilling 
their functions. 

Here then is a case of loss of individual characters in- 
creasing with the perfection of the colony. Amongst ants 
and termites, the social life of which arose quite indepen- 
dently of that of bees, the same course of events has been 
repeated. High intelligence and skill are confined to the 
workers, in which the reproductive organs are atrophied. 
The soldiers have powerful jaws used in defence of the 
camp, but they, too, are sexually incomplete. The females 
and males, in which the reproductive organs have attained 
huge proportions so that the bodies are little more than 
sacs containing the sexual elements, have no intelligence 
and very little skill. 

An extremely curious specialisation, consisting in the 
formation of honey-bearfng workers, occurs in some Mexi- 
can ants. Some of the workers of these races absorb so 
much honey that their bodies become swollen honey-bags. 
The limbs can no longer support the expanded body, and 
the insects, reduced to immobility, do not quit the burrows. 


Normal life has become impossible for these individuals, 
who soon die for the good of the community. When the 
normal workers or the sexual individuals are hungry, they 
approach the honey-bearers and take honey from their 

mouths. The honey-bearers have be- 

come no more than animated cupboards 

(Fig< 26) * 

The termites belong to quite another 
FIG. 26. A Honey- class of the group Insecta, but in their 
/AA \>\ \ case a similar sacrifice of the individual 

(Alter rJrenm.) 

to the state is practised. The females 
become transformed to shapeless bags of eggs. They 
cannot move, but remain secluded in the recesses of the 
"ant "-hill, where they lay as many as 80,000 eggs a day. 
The soldiers have become provided with jaws so enormous 
that these unsexed insects can perform no function other 
than defence of the colony. 

The partial reduction of individuality in social insects 
never goes so far as in the cases of the lower animals I have 
described. It may be stated as a general rule that increase 
in the perfection of organisation brings with it a more pr 
less complete preservation of individuality in the members 
of a community. 

I shall now examine to what extent this law can be 
applied in the case of man. 



Human societies Differentiation in the human race 
Learned women Habits of a bee, Halictus quadricinctus 
Collectivist theories Criticisms by Herbert Spencer and 
Nietzsche Progress of individuality in the societies of higher 

SOCIAL life is for the most part little developed amongst 
vertebrate animals. The birds and fishes which live in 
communities present no organisation of society even com- 
parable with that found amongst insects. There Is little 
advance in this respect in the case of mammals, and it is not 
until we come to man that highly organised societies are to 
be found. Man is the first vertebrate to develop an organ- 
ised social life. But, whilst in the insect world, instincts 
are of supreme importance in the regulation of the com- 
munity, there is little instinctive action in human com- 
munities. The consciousness of individuality, or egoism, 
is very powerful in human beings, and perhaps for that 
reason our ancestors made little progress in the development 
of social relations. 

Anthropoid apes adhere in little groups or in families 
without any true social organisation. Love of the neigh- 
bour, or altruism, appears to be a recent and feeble human 

Although the organisation of human society is far ad- 


vanced and division of labour very complete, there is no 
differentiation of the individuals comparable with what is 
found amongst insects. Although in animals so different as 
Siphonophora, bees, wasps, and termites the develop- 
ment of the community, proceeding along different lines, 
has brought into existence non-sexual individuals, there is 
no trace of this specialisation amongst human beings. 

Certain abnormalities in the condition of the sexual organs 
are occasionally found in men and women, but these cannot 
be compared with the production of sexless individuals that 
has taken place amongst other social creatures. I cannot 
accept the view that we are to see something analogous to 
the case of worker bees in the prohibition of sexual relations 
imposed by some religious systems on a certain number of 
individuals. But in any event there is little importance in 
this occurrence, which is rapidly becoming rarer. 

In recent times, both in Europe and the United States of 
America, there has been an active development of a feminin- 
ist movement impelling women towards higher education. 
Women, no longer content with the avocations of mother 
and housewife, have pressed into professions such as law 
and medicine. There is a steady increase in the number of 
women who study at the Universities, and countries like 
Germany, which have tried to exclude women from higher 
studies, will soon have to yield before an irresistible pres- 

Can we regard the results of this movement as analogous 
to the production of sexless workers which has taken 
place amongst social insects? I think not. It is un- 
doubtedly true that a certain number of young women, who, 
for some reason or other are unlikely to marry, devote them- 
selves to scientific study. In these cases, however, celibacy 
is the cause, not the result of the increased intellectual 


activity. On the other hand, it must be remembered that 
many women students of science eventually marry. In St. 
Petersburg, for instance, there were 1,091 women in the 
Medical School ; of these 80 were already married and 19 
were widows. Of the remaining 992, 436 or 44 per cent, 
married during the course of their studies. 

Observation of the femininist movement, which has lasted 
for more than forty years, shows that in most cases there 
is no tendency towards the formation of individuals re- 
sembling the infertile worker insects. Most lady doctors 
and learned women would like nothing better than to be 
the founders of a family. Even the women who have been 
most distinguished in the scientific world are no exception 
to the rule. In this relation it is very interesting to follow 
the details- of the life of Sophie Kowalevsky, one of the 
most notable of learned women. In her youth, when she 
began to study mathematics, she would not admit that feel- 
ings of love had any importance. Later on, however, when 
she felt herself growing old, these sentiments awoke in her 
to such an extent that on the day when the prize of the 
Academy of Sciences was bestowed on her, she wrote to 
one of her friends, " I am getting innumerable letters of 
congratulation, but by the strange irony of fate, I have 
never felt so unhappy." 

The cause of this discontent reveals itself in the words 
which she addressed to her most intimate woman friend. 
"Why is it," she said, "that no one loves me? I could 
give more than most women, and while the most ordinary 
women are loved, as for me, I am not loved." l 

It is, in fact, impossible to regard the celibacy of persons,, 
devoted to religion or to scientific studies as the beginning 
of a special organisation analogous to that of worker bees. 
1 Souvenirs d/enfance de S. Kowalevsky, 1895, pp. 301-311. 



However, it is still probable that in the human race a 
special differentiation has been established for the accom- 
plishment of different and essential functions. 

The organisation of human societies has certainly not fol- 
lowed the path by which social insects attained the forma- 
tion of sexless individuals. It much more closely re- 
sembles what has taken place in some isolated animal types. 
A solitary bee, named Halictus quadricinctus (Fig. 27), is 
characterised by the fact that the female does not die when 
she has laid her last eggs, as generally happens amongst 
insects, but remains alive to cherish her offspring. This 
final portion of her life does not last long, and the bee can- 
not play the prominent part of governess in a society of 
insects organised by this specialisation of elderly females. 
In the human race the individual life lasts 
longer and a division of labour takes place 
in the fashion suggested by Halictus quad- 

FIG. 27. Halictus An ordinary woman ceases to be fertile at 
between forty and fifty years old, that is to 
say, at a time when, according to statistics, 
she has still on the average twenty years to live. During 
this long period, she can perform an extremely useful 
function in society, a function resembling that of the 
old mothers of Halictus quadricinctus, and consisting 
chiefly in the bringing up and education of the children. 
Who does not know the extraordinary devotion of grand- 
mothers, and, as a general rule, of old women, who are 
extremely useful in bringing up children. And none the 
less, it must not be forgotten that, actually, old age begins 
too soon, that it is not what it ought to be under normal 
conditions, and that human life itself does not last nearly 
so long as it ought to do in ideal conditions. We may pre- 


diet that when science occupies the preponderating place in 
human society that it ought to have, and when knowledge 
of hygiene is more advanced, human life will become much 
longer and the part of old people will become much more 
important than it is to-day. 

The members of human society are not divided into 
sexual and neuter individuals as amongst insects, but the 
active life of every individual can be divided into two 
periods, the first one of productive activity, and the second 
of sterility but none the less devoted to work useful to the 
community. The essential difference between the two cases 
may be reduced to the contrast that whilst the individuals 
of which animal societies are composed are structurally in- 
complete, in human societies the individual preserves his 

We come, then, to the result that the more highly 
organised a social being may be, so also the more highly 
developed is his individuality. It follows that amongst the 
theories which seek to control social life, those are the best 
which leave a field sufficiently wide and free for the develop- 
ment of individual initiative. The ideal which has been so 
often advocated and according to which the individual is to 
be sacrificed as completely as possible to society, cannot be 
regarded as in harmony with the general law of organic 
associations. Special conditions exist in social life in which 
great sacrifices are inevitable, but such an arrangement 
cannot be considered as general and permanent. We may 
predict that the more human beings succeed in advancing 
communal life, the fewer cases there will be in which the 
individual has to be sacrificed. 

In the hope of subduing the egoism rooted in human 
nature, moralists have preached renunciation of individual 
happiness and the need of subordinating it to the good of 

Q 2 


the community. Very often such doctrine has borne little 
fruit, but there are cases where it has been embraced with 
such ardour that men and, still more, young women have 
been led to sacrifice their well-being for what they have 
taken to be the common good. However it may involve 
self-abnegation, there has been continued insistence on the 
duty of sacrificing the individual to the community. 

The existing great inequalities in the distribution of 
wealth have revived doctrines the object of which is to 
redress such injustice. For more than a century, different 
forms of socialism have claimed to formulate rules for the 
amelioration of mankind. They agree in a verdict 
against existing conditions, but follow different paths 
in their proposals for the reformation of society. The 
varieties of socialism are so numerous that it is difficult 
even to define the word. Although collectivist theories 
have lost much of their early thoroughness, they are still 
far from admitting the just claims of the individuals con- 
stituting the society. At socialist assemblies and con- 
gresses the resolutions adopted frequently proclaim 
aggressively the sacrifice of the rights of the individual. 
The members of one socialist party have been seen refusing 
the collaboration of newspapers which are not the official 
organs of the party, or declining any co-operation with a 
government they have proscribed. In strikes organised by 
socialists, work is forbidden to men who ardently desire it. 
Recently printers have refused to set up newspapers the 
opinions of which they did not share, and even doctors 
have been known to decline to treat those belonging to 
another political party. 

It is no new charge against collectivists that they would 
encroach too much on individual liberty. They reply that 
" in social-democratic society of the future, tyranny and 


oppression will be impossible. The secret of the bond will 
reside in a discipline totally different from the inanimate 
obedience of the soldier, a discipline depending on a willing 
submission of the individual to the group because of the 
common object." 1 But such discipline and submission 
may go so far that the conscience of the individual is seri- 
ously offended. And so amongst the socialists themselves 
there has arisen a small group which declines to accept this 
submergence of the individual in the whole. This group 
is composed of anarchists, who, in the name of liberty and 
the individual, attack the property and sometimes the lives 
of their opponents. 

It appears that there has been a notable evolution of 
collectivist theories in the century or more in which the 
abolition of human misery has been an accepted problem. 
Whilst there was formerly advocated the total abolition of 
private property and the establishment of phalansteries for 
communal life, at the present time the demand is limited 
to the nationalisation of the means of production, leaving 
housing and food to be provided by individual property. 

Through a publication, of M. Kautsky, one of their best 
known representatives, the social democrats have announced 
that "the nationalisation of the land does not necessarily 
bring with it the abolition of private dwellings. The custom- 
ary attachment of the dwelling to agricultural employment 
will cease, but there is no reason why the peasants' houses 
should become collective property." "Modern socialism 
does not exclude individual property in food. One of the 
most important, perhaps the most important factor, in mak- 
ing human life happy and adding to its pleasures is the 
possible attainment of a private house. Collective owner- 

1 W. Henberg, Sozialdentokratie und Anarchismus, 1906, p. 17. 

2 Le problems agraire, 1905, p. 147. 


ship of the land does not exclude this." It is very difficult 
to separate house and garden, especially from the point of 
view of considering the pleasures of life. A garden fur- 
nishes the opportunity for endless improvements, many of 
which cannot be separated from the idea of individual pro- 
perty. The concessions which collectivists have been com- 
pelled to make show conclusively the importance of private 

Notwithstanding such modifications, many voices have 
been raised against the prospect of the socialisation of the 
means of production and the concomitant limitations of 
individual enterprise. The great English philosopher, 
Herbert Spencer, 1 against whom narrowness of view or 
conservatism could be urged, energetically attacked collec- 
tivist doctrines as tending to reduce human individuality to 
a dead level. By a series of cogent instances, he showed 
the evil results of the best intentioned efforts to equalise 
opportunities and to abolish poverty. He foretold that 
slavery would be the real outcome if the State interfered too 
much in spheres that ought to be left to individual enter- 
prise. He believed that the institution of a collectivist State 
would bring great dangers. 

Nietzsche has attacked socialism with his customary 
exaggeration. " Socialism," 2 he wrote, " is the fanatical 
younger brother of dying despotism, whose goods he 
wishes to inherit ; his efforts are, in the deepest sense of the 
word, reactionary. He wishes a wealth of power in the 
State greater than despotism ever enjoyed, but he goes 

1 "The Coming Slavery" in Man versus the State, 1888, p. 18. 

2 Human, too Human. French translation, 1899, pp. 405-407. A 
German critic has reproached me for my ignorance of Nietzsche's works. 
I have read several of them, but the mixture of genius and madness in 
them makes them difficult to use. In this connection Moebius' volume. 
Ueber das Pathologische bet Nietzsche (Wiesbaden, 1902), is of interest. 


beyond all the past inasmuch as he strives absolutely to 
stifle the individual; for him the individual is a useless 
efflorescence of nature to be tamed into a useful organ of 
the community." Further, " Socialism at least teaches 
brutally and convincingly the danger of concentrating 
power in the State, for it is a covert attack on the State 
itself. When ks harsh voice raises the war-cry ' Let the 
State control as much as possible,' the cry will at first 
become louder ; but soon another phrase will grow equally 
clamant, ' Let the State control as little as possible.' " 

It is most probable that no shade of socialism will be able 
to solve the problem of social life with a sufficient respect 
for the maintenance of individual liberty. None the less 
the progress of human knowledge will inevitably bring 
about a great levelling of human fortunes. Intellectual 
culture will lead men to give up many things that are 
superfluous or even harmful, and that are still thought in- 
dispensable by most people. The conceptions that the 
greatest good fortune consists in the complete evolution of 
the normal cycle of human life and that this goal can be 
reached most easily by plain and sober habits will convince 
men of the folly of much of the luxury that now shortens 
human existence. Whilst the rich will choose a simpler 
mode of life and the poor will be able to live better, none the 
less, private property, acquired or inherited, may be main- 
tained. Evolution must be gradual and much effort and 
new knowledge is required. Sociology, a new-born science, 
must learn of biology, her older sister- Biology teaches us 
that in proportion that the organisation becomes more com- 
plex, the consciousness of individuality develops, until a 
point is reached at which individuality cannot be sacrificed 
to the community. Amongst low creatures such as Myxo- 
mycetes and Siphonophora, the individuals disappear 


wholly or almost wholly in the community ; but the sacrifice 
is small, as in these creatures the consciousness of indi- 
viduality has not appeared. Social insects are in a stage 
intermediate between that of the lower animals and man. 
It is only in man that the individual has definitely acquired 
consciousness, and for that reason a satisfactory social 
organisation cannot sacrifice it on pretext of the common 
good. To this conclusion the study of the social evolution 
of living beings leads me. 

It is plain that the study of human individuality is a 
necessary step in the organisation of the social life of 
human beings. 




Oriental origin of pessimism Pessimistic poets Byron 
Leopardi Poushkin Lermontoff Pessimism and suicide 

IN the attempt to formulate a pessimistic theory of human 
nature, we are naturally led to ask why it is that so many 
famous men have come to a purely pessimistic conception of 
human life. 

Pessimism, although it has been most prominent in 
modern times, is extremely old. Everyone knows the pessi- 
mistic wail of Ecclesiastes, written nearly ten centuries 
before our era : " Vanity of Vanities, all is vanity." 
Solomon, the supposed author, states that he " hated life, 
because the work that is wrought under the sun is grievous 
unto me, for all is vanity and vexation of spirit " (Eccl. ii., 


Buddha raised pessimisim to the rank of a doctrine. All 
life seemed to him sorrow. "Birth is sorrow, old age is 
sorrow, disease is sorrow, union with one whom we do not 
love is sorrow, separation from one whom we love is sorrow, 
not to gratify desire is sorrow, in short, our five bonds 
with the things of the earth are sorrow." 1 This Buddhistic 

1 Quoted by Oldenberg, Le Bouddha, French translation, Paris, 1894, 
p. 214. 


pessimism has been the source of most of the modern 
pessimistic theories. 

Pessimism arose in the East and was much in vogue in 
India even apart from Buddhism. In the poems known 
under the name of Bhartrihari, and dating from the begin- 
ning of the Christian era, human life has been commiserated 
in the following fashion. " One hundred years are the 
limit of the life of man ; night takes half of them, half of 
the other half is childhood and old age, the rest is rilled 
with diseases, with separations and the misfortunes that 
come from them, with working for others and with wasting 
one's time. Where can happiness be found in an existence 
most like to the bubbles in broken water?" "Man's 
health is destroyed by every kind of care and disease. 
When fortune comes to him, evil follows as if by an open 
door. Death takes all human beings, one after the other, 
and they can offer no resistance to their fate. What is there 
assured amongst all that the mighty Brahma has created? " l 

Pessimistic theories spread from the Asiatic East to 
Egypt and Europe. Three centuries before the Christian 
era, there arose the philosophy of Hegesias, which main- 
tained that experience was generally deceptive and that en- 
joyment was quickly followed by satiety and disgust. Ac- 
cording to him, the sum of pain surpassed the sum of 
pleasure in life, so that happiness was unattainable, and in 
reality never existed. It was vain to seek pleasure and hap- 
piness, as these could not be realised. It was better to try to 
be indifferent, dulling feeling and desire. In fact, life was no 
better than death, and it was often preferable to end it by 
suicide. Hegesias was called Pisithanatos, the adviser of 
death. " Listeners thronged around him, his doctrine 
spread rapidly, and his disciples, persuaded by his voice, 

1 P. R^gnaud, " Le pessimisme brahmanique," in Annales du Muse'e 
Guimet, 1880, vol. i, pp. no-ill. 


gave themselves to death. Ptolemy was perturbed by it, 
and fearing that the dislike of life would become contagious, 
closed the school of Hegesias and exiled its master." 1 

The pessimistic tendency sometimes appears in the writ- 
ings of many Greek and Latin philosophers and poets. 
Seneca wrote : " The spectacle of human life is lamentable. 
New misfortunes overwhelm you before you have freed 
yourself from the old ones." 2 

It is in modern days, however, that there has been the 
greatest spread of pessimism. 

Besides the philosophical theories of the last century, 
those of Schopenhauer, von Hartmann and Mailaender, 
which I discussed sufficiently in The Nature of Man, poets 
have formulated a pessimistic view of life. Even Voltaire 
was a pessimist in the following lines : 

Alas 1 what are the course and the goal of life ? 

Only follies and then the darkness. 
Oh Jupiter ! in creating us you made 

A heartless jest. 

In The Nature of Man I described Byron's expression 
of his conception of the evils of human life. Soon after the 
death of the great English poet, a celebrated Italian poet, 
Giacomo Leopardi, sounded a note of abandoned pessim- 

Here are words which he addressed to his own heart 3 : 
" Be quiet for ever, you have beaten enough, nothing is 
worthy of your beating and the earth is not worthy of your 
sighs. Life is nothing but bitterness and weariness, there 
is nothing else in it. The world is nothing but mire. 
Repose from now onwards. Be in despair for ever. Destiny 
has given us nothing but death. Despise henceforth your- 

1 Guyau, La Morale d 1 Epicure, 4th edition, 1904, p. 116. 

2 Ad Marciam, chap. x. 

3 Poesies et oeuvres morales, by Leopardi. Translated into French 
i8o, p. 49. 


self and nature, and the shameful concealed power which 
decrees the ruin of all and the infinite variety of all." 

Leopardi makes his readers witnesses of his distraction 
and his grief : " I shall study the blind truth " he wrote in 
a poem dedicated to Charles P^poli " I shall study the 
blind fates of things mortal and immortal. Why humanity 
came into existence, and was burdened with pain and 
sorrow, to what final end destiny and nature are driving it, 
for whose pleasure or advantage is our great pain, what 
order, what laws rule this mysterious universe which wise 
men cover with praise, and I am content to wonder at " 
(ibid., p. 15). 

Quite a school of poets has been developed, singing 
the pain of the world, the " Weltschmerz " of German 
authors, amongst whom Heine and Nicolas Lenau are 
specially distinguished. 

Russian poetry was born under the influence of Byron- 
ism, and its best exponents, Poushkin and Lermontoff, 
often laboured over the problem of the object of human 
existence, finding only sad answers. Poushkin, who is 
justly regarded as the father of lyric poetry in Russia, 
stated his pessimistic conception in the following lines : 

Useless gift, gift of chance. 

Life, why wert thou given me? 

And why from the beginning art thou doomed 

Irrevocably to death? 

What unfriendly power 
Has drawn me from the darkness, 
Has filled my soul with passion, 
And breathed doubt into my soul? 

There is no goal for me, 
My heart and my soul are empty ; 
And the dull emotion of life 
Has filled me with black care. 


Recently, Mde. Ackermann, in a series of short poems, 
has given voice to the grief caused to her by the world and 
life as they are, although she does not state exactly the 
reason of her bitter complaints. 

Whilst pessimistic philosophers and poets reflect the 
thoughts and feelings of their contemporaries, it is certain 
that they also seriously influence their readers. And so 
there has come into existence a deeply rooted conviction 
that the miseries of human life are far from being counter- 
vailed by its happiness. Probably such ideas have influ- 
enced the number of suicides. We do not know with any 
certainty the real motives of most cases of self-destruction, 
but it cannot be denied that the trend of modern thought 
has played an important part. According to statistics, the 
chief causes of suicide are "hypochondria, melancholia, 
weariness of life, and unbalancing of the mind." Thus from 
the Danish statistics it appears (and Denmark is the country 
in which suicide is most prevalent) that of 1,000 cases of 
suicides of males, between 1866 and 1895, 224, or one- 
quarter, were referred to the causes I have just mentioned. 
In the case of women, the corresponding figures are higher, 
amounting to nearly one-half (403 out of 1,000). The 
second most common cause of male suicides is alcoholism 
(164 in ijooo). 1 It is very probable that pessimism was the 
determining condition in most of the suicides referred to 
these two categories of causes. Leaving out of the question 
the true cases of mental alienation, amongst the victims of 
melancholia, hypochondria and weariness of life, in whom 
the mental condition was not pathological in the strict sense 
of the word, there must have been many who killed them- 
selves because their view of life was pessimistic. And 
amongst the victims of drink, there are many who take to 

1 These facts are taken from Westergaard, 2nd edit., 1901, p. 649. 


alcohol because they are convinced that life is not worth 

The progressive increase in the numbers of suicides in 
modern times is an index of the great influence of pessi- 
mism. There have been even societies for the promotion 
of suicide. In such a society, founded in Paris in the begin- 
ning of last century, members placed their names in an urn, 
to be drawn by chance. He whose name was drawn had 
to kill himself in the presence of the other members. 
According to its rules, this society admitted only persons 
of honour who must have had experience of "the injustice 
of man, the ingratitude of a friend, the infidelity of a wife 
or mistress, and who, moreover, for many years had had a 
void in their souls and a distaste of what this world can 
offer." 1 

Although such societies no longer exist, individuals con- 
tinue to put their lives to an end, in greater numbers every 

1 Dieudonn, Archiv fiir Kulturgeschichte, 1903, vol. i, p. 357, 



Attempts to assign reasons for the pessimistic conception of 
life Views of E. von Hartmann Analysis of Kowalevsky's 
work on the Psychology of Pessimism 

IN view of the facts I brought together in my last chapter, 
there is occasion to inquire if it be possible to discover the 
intimate mechanism by which men arrive at a conception of 
life as an evil to be got rid of as quickly as possible. Why 
do so many think that man is less happy than the beasts, 
and that cultured and intelligent men are more unhappy 
than those who are ignorant or feeble-minded ? 

I have related how in a society of friends of suicide, 
injustice and unfaithfulness were regarded as prime factors 
in arousing a distaste for life. Shakspeare made Hamlet 
exclaim that if it were possible to put an end to our days no 
one would continue to live : 

For who would bear the whips and scorns of time, 
The oppressor's wrong, the proud man's contumely? 

For Byron, besides diseases, death and slavery, the evils 
that we see, there are others: 

And worse, the woes we see not which throb through 
The immedicable soul, with heart-aches ever new. 

In many of his works he insists on the feeling of satiety 


which was almost continually upon him. Every sensation 
of pleasure that came to him was rapidly succeeded by a 
still stronger feeling of disgust. 

Heine thought that existence was evil and saw 

.... across the hard surfaces of the rocks 
The homes of men and the hearts of men 
In the one as in the others, lies, imposture and misery. 

As I urged in The Nature of Man, consciousness of 
the shortness of human life has been an important factor 
in exciting pessimism, and we find this theme recurring in 
pessimistic writers. Leopardi returns to it again and again 
in his poems. " Falling in peril of death from some mys- 
terious disease," he said in his Souvenirs, "I lamented 
over my sweet youth and the flower of my poor days which 
was to fall so soon, and often in the midnight hours wove 
from my sorrows, by the pale light of my lamp, a sad poem, 
and in the silence of the night wept over my fleeting life, 
and half fainting, sang to myself my funeral song " (loc. 
cit., p. 28). The bas-relief on an ancient tomb, represent- 
ing the departure of a young girl who took farewell of 
her friends, suggested to Leopardi the following thoughts : 
" Mother, who from their birth makes her family of living 
beings tremble and weep, Nature, monster unworthy of our 
praise, who brings into the world and nurtures only to kill, 
if the premature death of a mortal be evil, why do you bring 
it on so many innocent heads? If it be a good, why do you 
make it sad for those who go and for those left behind ? 
Why is it the hardest grief to console ? The only relief 
from our woes is death, death, the inevitable end, the immu- 
table law which you have established for human beings. 
Why, alas, after the sad voyage of life, do you not make 
the arrival joyful ? This certain end, this end which is in 
our souls all our lives, which alone can soothe our troubles, 


why do you drape it in black and surround it with mournful 
shades ? Why do you make the harbour more terrible than 
the open seas?" (loc. cit., p. 55). 

The three chief grievances injustice, disease, and death 
often come together. From the anthropomorphic point 
of view fate is represented as a sort of wicked being who 
commits injustice by visiting all kinds of evils on mankind. 

A pessimistic conception of life is arrived at by a complex 
psychological process in which both feelings and reflection 
are involved, and hence it is difficult to analyse it satisfac- 
torily. Formerly, therefore, writers were content with 
general and very vague estimates of the process by which 
we may become pessimists. Ed. von Hartmann has tried 
to deal more exactly with this inner process of the human 
mind. In the first place, he lays stress on the fact that 
pleasures always bring less satisfaction than pains bring 
grief. False notes in music, for instance, are more painful 
than the best music is delightful. The pain of toothache 
is much more violent than the pleasure when relief comes. 
So also with all diseases. In love, according to Hartmann, 
the pleasure is always very greatly over-balanced by the 
pain. Muscular work brings pleasure only in a very small 
degree, and devotion to science and art and intellectual 
work in general brings more pain than pleasure to the 
votaries. As the result of an analysis, Hartmann is con- 
vinced that there is much more pain than pleasure in the 
world. Pessimism is founded upon the essential nature of 
human feelings. 

M. Kowalevsky, 1 a German philosopher at Koenigsberg, 
adopting the modern habit of measuring mental processes 
as exactly as possible, has recently published an attempt 

1 Kowalevsky, Studien zur Psychologic des Pessitntsmus, Wiesbaden, 



to analyse pessimism psychologically. Although this has 
not solved the problem, it is extremely interesting as an 
instance of the application of the methods now being 
adopted in modern psychology. 

M. Kowalevsky took advantage of all the known methods 
of estimating the relative values of our emotions; he tried 
to make use of the notes of Munsterberg, another living 
psychologist who kept a journal in which he set down daily 
his psychical and psycho-physical impressions. The object 
of the work had no relation to the question of pessimism, 
and for that reason Kowalevsky thought that it was speci- 
ally important in his investigations. 

Munsterberg was not content with the existing classifica- 
tion of emotions as agreeable or painful. He subdivided 
them much further. He recognised, for instance, emotions 
of tranquillity and excitement, serious and pleasant impres- 
sions. Having completed the reckoning, Kowalevsky 
came to the conclusion that his colleague, who was by no 
means a pessimist, but a psychologist of well-balanced 
mind, experienced many more painful emotions (about 60 
per cent, as compared with 40 per cent.) than agreeable 
emotions. " Such a result is in favour of pessimism," con- 
cluded Kowalevsky. 

However, he went beyond the foregoing enquiry. By 
several other methods, he tried to gain an exact idea of the 
value of our emotions. He visited elementary schools in 
order to investigate the pleasures and pains of the scholars. 
In the case of 104 boys, of eleven to thirteen years of age, 
he found that pain was much more deeply felt than corre- 
sponding pleasure. Thus, while in 88 cases illness was 
set down as an evil, only in 21 was health reckoned as a 
good. One-third of the pupils noted down war amongst 
evils, whilst only one noted peace amongst the good things. 


Poverty was written down thirteen times as an evil, against 
twice in which riches were put down as a good. In another 
series of investigations, Kowalevsky took notes on the 
pleasures and pains felt by pupils of the two sexes attend- 
ing the same school. The result was that the greatest evil, 
according to them, was illness, noted 43 times, then death 
42 times, after which came fire 37 times, hunger 23 times, 
floods 20 times. Amongst the good things, the first place 
was given, as might have been expected, to games (30) and 
the second to presents. 

As Kowalevsky did not find that such investigations 
could solve the problem, he tried to discover a more exact 
method. With this object, he turned to different sensa- 
tions, such as those of smell, hearing and taste, to which 
he applied methods of exact measurement. In the case 
of taste, for instance, he determined the minimum quantity 
of different substances which could excite definitely plea- 
sant or unpleasant sensations. In his experiments, Kowal- 
evsky found that doses which gave bad tastes were not 
balanced by those which gave good tastes. For instance, 
to neutralise the unpleasant taste of quinine, it was neces- 
sary to employ a much larger quantity of sugar. He was 
specially pleased with one experiment. Four persons were 
given definite mixtures of sugar and quinine in order to 
discover the proportion of the two substances necessary to 
obtain a neutral sensation. He found that to take away 
the bad taste of quinine, it was necessary to double the 
quantity of sugar given. Similarly with smells, he found 
that those which were unpleasant were appreciated much 
more strongly than those which were pleasant. Here, *" 
then, was a series of scientific results supporting the view 
of the pessimists. Must we really conclude from them 
that the world is very badly arranged? The analysis of 

R 2 


good and bad temper made by Kowalevsky is in favour 
of such an interpretation. In order to estimate these con- 
ditions of mind, he measured the gait, that is to say, the 
number of steps taken in a minute. This method depended 
upon the following idea. It is an accepted view that the 
condition of mind is shown by the rapidity of the human 
walk ; we have only to compare the slow pace of a man in 
deep grief with the rapid steps of a man in a state of joy. 
Pain, as a general rule, depresses, while joy stimulates 
voluntary movements. The result of the measurements 
taken according to this method give a new argument in 
favour of pessimism. However, it is useless to attempt 
to analyse these figures on which Kowalevsky had to em- 
ploy the integral calculus, because the principle of his 
method cannot be supported. As a matter of fact, the 
rapidity of walking is an index of the degree of excitation, 
and not of the happy or unhappy condition of the mind. 
When a person suddenly undergoes a strong impression, 
either pleasant or unpleasant, he takes to walking actively 
about in his room, and may even want to go out of doors 
to walk more quickly. A letter which has been received 
and which gives some unexpected news, as for instance 
of the infidelity of a person one loves, or of an inheritance 
which one did not expect, produces a condition of excite- 
ment shown chiefly by rapid walking. Many orators and 
professors have to make gestures and to walk about in 
the course of their lectures. A man of science to whom 
some new idea comes and who wishes to out, rises 
from his chair and begins to walk. But not only on such 
pleasant occasions, but when one has to face an insult or 
an act of defiance which makes one very angry, the need 
to walk actively is felt. It is therefore impossible to utilise 
records of movements in the study of the pessimistic state 
of mind. 


M. Kowalevsky employed still another mode of attack- 
ing the problem. He examined the recollection of painful 
or pleasant impressions. He asked the children of both 
sexes, whom he was investigating, questions which gave 
him indications as to whether pleasures or pains made the 
more lasting impression on the memory, and he registered 
the answers. The result, which agreed with what had 
already been obtained by Mr. Colegrove, an American 
psychologist, was unfavourable to the pessimistic view. 
He found, in fact, that in the majority of cases (70 per 
cent.) recollection of pleasant impressions predominated. 
However, in such investigations there is a facile source of 
error arising from the condition of mind of those who are 
being questioned. It is probable that Kowalevsky made 
his enquiry in school during recreation time, when most 
of the pupils were free from the boredom of the actual 
class. When we are happy the tendency exists in us to 
recall pleasant impressions of the past. If the enquiry had 
been made during a difficult or wearying lesson, or on 
children shut up in a hospital, or undergoing punishment, 
it is probable that the result would have been reversed. 

It is evident that all such attempts to solve a problem 
so complex as that of pessimism, even by the so-called 
exact methods of physiological psychology, cannot lead to 
any convincing result. Thus Kowalevsky's different in- 
vestigations led to contradictory conclusions. Whilst some 
of his series of facts supported the pessimistic conception, 
others were opposed to it, and he obtained no definite 
general conclusion. How can one expect to apply a 
method of measurement to sensations and emotions so 
different, not only from the qualitative point of view, 
but also in relation to their intensity ? Take, for instance, 
the case of an individual who has experienced in one day 
nine sensations which were painful and one which was 


agreeable. According to the valuation of experimental 
psychologists, he ought to have reason to become a pessi- 
mist. However, this may be far from the case, if the nine 
painful impressions were much weaker than the single 
happy impression. The first were provoked by small 
wounds to his pride, fleeting pains of no importance, and 
small losses of money, whilst the happy emotion came from 
receiving a love letter. The sum of the ten impressions 
would be a happy one, and might well put him in an opti- 
mistic frame of mind. The learned attempts of experimental 
psychologists must be abandoned, as incapable of illumina- 
ting the problem. If, however, the human spirit still seeks 
some means of explaining the psychology of pessimism, 
there remains only the less subtle method given by the bio- 
graphical study of human beings. 



Relation between pessimism and the state of the health 
History of a man of science who was pessimistic when young, 
and who became an optimist in old age Optimism of 
Schopenhauer when old Development of the sense of life 
Development of the senses in blind people The sense of 

ANIMALS and children in good health are generally cheerful 
and of optimistic temperament. As soon as they fall ill 
they become sad and melancholy until their recovery. We 
may infer from this that an optimistic view is correlated 
with normal health, whilst pessimism arises from some 
physical or mental disease. And so in the case of the 
prophets of pessimism, we may seek for the origin of their 
views in some affliction. The pessimism of Byron has 
been attributed to his club-foot, and that of Leopardi to 
tuberculosis, these two nineteenth century exponents of pes- 
simism having died whilst young. Buddha and Schopen- 
hauer, on the other hand, reached old age, whilst Hart- 
mann died when sixty-four years old. Their diseases at the 
time when they formed their theories could not have been 
very dangerous, and none the less they took a most gloomy 
view of human existence. The recent historical investiga- 
tions of Dr. Iwan Bloch 1 make it very probable that 
Schopenhauer, in his youth, contracted syphilis. There 
1 Meduinische Klinik, 1906, n. 25 and 26. 


has been found a note-book of the great philosopher in 
which he wrote down the details of the severe mercurial 
treatment which he had to undergo. The disease, how- 
ever, was not contracted until several years after the appear- 
ance of his great pessimistic work. 

Although we must attach due weight to the connection 
between disease and pessimism, we can assure ourselves 
that the problem is more complex than it appears at first 
sight. It is well known that blind people often enjoy a 
constant good humour, and, amongst the apostles of op- 
timism, there has been the philosopher Duering, 1 who lost 
his sight during his youth. 

Moreover, it has been noticed that persons affected with 
chronic diseases frequently have a very optimistic concep- 
tion of life, whilst young people in full strength may 
become sad, melancholic, and abandoned to the most ex- 
treme pessimism. Such a contrast has been well described 
by Emile Zola in his novel La Joie de Vivre, where a 
rheumatic old man, tried by severe attacks of gout, main- 
tained his good humour, whilst his young son, although 
vigorous and in good health, professed extreme pessi- 

I have a cousin who lost his sight in early youth. When 
he grew up he formed a most enviable judgment of life. He 
lived in his imagination and everything in life seemed to 
him good and beautiful ; he married, and pictured his wife 
to himself as the most beautiful woman in the world, and 
thus he feared nothing more than the recovery of his sight. 
He had adapted himself to live without sight, and was con- 
vinced that the reality was much lower than his imagina- 
tion. He feared that if he were able to see his wife she 
would appear to him less beautiful. 

1 Der Werth des Lebens. 


I know a girl twenty-six years old, blind from her birth, 
the subject of infantile paralysis and liable to fits of 
epilepsy. She is nearly an idiot, lives- in a carriage, and 
sees life from its best side. She is certainly the most 
happy member of all her family. 

The good humour and megalomania of those affected 
with general paralysis of the insane also is well known. All 
such examples show that pessimism cannot be explained as 
depending on bad health. 

Examination of the state of mind of a pessimist may 
throw some light on the subject. There has been within 
my own circle a typical case of a person who went through 
a phase of life in which everything seemed as gloomy as 
possible. My intimate knowledge of him makes it possible 
to apply my observations to the matter under discussion. 

The subject was born of parents of good health and in 
comfortable circumstances, so that, from the beginning of 
his life, he was surrounded by a favourite environment. He 
lived in the country and escaped the diseases of childhood, 
so that he reached maturity in good health, and passed well 
through college and the university. Science attracted him, 
and he had the ambition to become a distinguished investi- 
gator. He threw himself into a scientific career with zeal 
and ability. His ardent disposition, although certainly 
favourable to work, was the cause of many troubles. He 
wished to succeed too quickly, and the obstacles he encoun- 
tered embittered him. As he thought himself naturally 
talented, he conceived it to be the duty of his seniors to aid 
his development. And so, when he met with natural and 
very common indifference from those who had already b- 
come successful, the young man thought that there was a 
plot against him, to bring to nothing his scientific talents. 
From this view, many quarrels and difficulties arose, and as 


he could not overcome these sufficiently quickly, he fell 
into a mood of pessimism. In this life, he said to himself, 
the main thing is to adapt oneself to external conditions. 
According to Darwin's law of natural selection, the indivi- 
duals who do not succeed in adapting themselves go to the 
wall. The survivors are not the best but only the most 
cunning. In the history of the earth it has been seen that 
many lower animals have long survived creatures much 
higher in organisation and general evolution. Whilst so 
many of the higher mammals, the nearest relatives of man, 
have been crushed out of existence, simpler animals, such 
as evil-smelling cockroaches, have survived from the re- 
motest times, and multiply in the neighbourhood of man 
in despite of his efforts to exterminate them. The animal 
series and human evolution itself show that delicacy of the 
nervous system, with its concomitant extreme development 
of the sensibilities, hinders the power of adaptation and 
brings with it insuperable evils. The least blow to his pride, 
or a slighting word from a comrade, threw this pessimist 
into a most painful condition. No, he would cry, it would 
be better to be without friends, if one is to be wounded so 
deeply by them. It would be best to seclude oneself in 
some remote spot and be engrossed in one's work. He was 
very impressionable and a lover of music, and from his 
visits to the opera, he retained in his mine! an air from the 
" Flute enchantee." " Were I as small as a snail, I would 
hide myself in my shell." His moral hypersensibility was 
associated with physical hyperaesthesia. Noises of all 
kinds, such as the whistling of railway-trains, the cries of 
street-vendors, or the barking of dogs, excited extremely 
painful sensations. The least trace of light prevented him 
from sleeping at night. The unpleasant flavour of most 
drugs made it impossible for him to take medicine. He 


agreed thoroughly with the pessimistic philosophers who 
declare that the ills of life far surpass the good things. He 
required no experiments on the sense of taste to convince 
him. He believed that the organisation of his body pre- 
vented him from becoming adapted to external conditions 
and that he would have to disappear like the mammoth and 
the anthropoid apes. 

The course of his life confirmed the convictions of our 
pessimist. He had no private fortune and married a woman 
who became affected with tuberculosis, and so was con- 
fronted with the greatest evils of existence. A young lady, 
hitherto in good health, contracted influenza in some 
northern town. It was a mere nothing, said the doctors; 
influenza is everywhere and no one escapes it; after a little 
patience and rest, she will be well again. However the 
" influenza " persisted and brought with it feebleness and 
wasting. The doctors then found that there was a little 
dullness in the apex of the left lung, but as there was no bad 
family history, there was nothing to fear. I need not 
describe the familiar course of events. The trifling influ- 
enza was replaced by degeneration of the left lung, and 
brought death after four years of great suffering. Towards 
the end, when there was no hope, the patient found her only 
solace in morphine. Under the influence of that drug, she 
passed hours free from pain and in relative calm, but her 
excited imagination passed almost into hallucination. 

It is not surprising that the death of his wife was a severe 
shock to the husband. His pessimism became complete. 
He was a widower at the age of twenty-eight years, and, in 
his condition of mental and physical exhaustion, took to 
morphine like his wife. He knew that it was a poison which 
would complete the ruin of his constitution and make his 
work impossible. But what was the value of his life? As 


his organisation was too nervous for him to adapt himself 
10 external conditions, was it not as well to come to the aid 
of natural selection and so make room for others ? As it hap- 
pened, a large dose of morphia did not solve the problem. 
It produced in him a condition of extraordinary happiness 
combined with extreme physical weakness. Little by little 
the instinct of life awoke in him, and he resumed his work. 
Pessimism, however, remained the fundamental quality in 
his character. Life was not worth the pains necessary to 
protect it. It would be a true crime to bring into the world 
other living beings doomed to elimination by natural selec- 
tion. Moral and physical sensibility, as they continued to 
develop, brought with them so much evil that there could 
be no good end. The " injustice" of those who were un- 
willing to " understand " him made life painful to the man 
himself and to those about him. The closest absorption 
and hard work made his existence more tolerable, but his 
pessimistic conception was not in the least altered. Thus, 
he was easily driven to morphia for consolation, when he 
suffered from some act of "injustice" or vexation. A 
severe fit of poisoning, however, stopped this excess. 

Years passed. When he discussed with his friends the 
problem of the goal of human life and similar topics, he 
was always ardent in supporting the point of view of pes- 
simism. However, he occasionally wondered if his pleading 
for this were really sincere. As his nature was honest and 
frank, this question which he put to his conscience appeared 
most curious to him. Analysis of what passed in his mind 
revealed to him a change. It was not that his conceptions 
had changed in the course of years, but rather his feelings 
and sensations. As he was now in full maturity, between 
forty-five and fifty years old, he found that there was a great 
change in the intensity of these last. Disagreeable sounds 


did not trouble him to the same extent as formerly, and 
he was undisturbed by the caterwauling of cats or by harsh 
street cries. As his hypersensibility diminished his 
character became more tolerant. Even the injustices or 
wounds to his pride which formerly drove him to mor- 
phia, no longer provoked in him any painful reaction. He 
could easily conceal the bad effect of these upon him, and 
no longer felt them with the same intensity. Thus his 
character had become much more supportable to those with 
him, and much better balanced. 

" It is old age which is come upon me," he cried ; " I feel 
painful impressions much less acutely and pleasant impres- 
sions have less effect on me. The relative proportions of the 
two remain as before, that is to say, unpleasant things still 
impress me much more strongly than pleasant things." By 
analysing and comparing his emotions, he discovered some- 
thing new, in fact that some impressions were, so to speak, 
neutral. As he was less sensitive to unharmonious sounds, 
and at the same time less affected by music itself, he found 
himself in a more tranquil condition. Awakening in the 
middle of the night, he experienced a kind of happiness 
which reminded him -of that formerly produced by mor- 
phine, and which was characterised by his hearing no sound, 
either pleasant or unpleasant. He became less disgusted 
by drugs, but at the same time indifferent to the pleasures 
of the table which he had appreciated in his youth. He 
also delighted in consuming more and more simple food. 
A piece of black bread and a glass of water became real 
treats to him. Insipid dishes, which he formerly despised, 
were now specially agreeable to him. 

Just as in the evolution of art, violent coloration has 
yielded to the low tones of Puvisde Chavannes, as views of 
fields and meadows are preferred to those of mountains and 


lakes ; just as in literature, tragic and romantic studies have 
been successfully replaced by scenes of daily life, so the 
psychical development of my friend displayed a similar 
change. Instead of taking his pleasure in mountains or in 
places famed for their picturesqueness, he was content to 
watch the budding of the leaves of the trees of his garden, 
or a snail overcoming its fears and putting out its horns. 
The simplest occurrences, such as the lisping or the smile 
of a baby or the first words of a child, became sources of 
real delight to this elderly man of science. What was the 
meaning of these changes which took so many years to 
be accomplished? It was the growth of his sense of life. 
The instinct of life is little developed in youth. Just as a 
young woman gets more pain than pleasure from the earlier 
part of her married life, just as a new-born baby cries, so 
the impressions from life, especially when they are very 
keenly felt, bring more pain than pleasure during a long 
period of human life. The sensations and feelings are not 
stable; they undergo evolution, and when that takes place 
more or less normally, it brings about a state of psychical 

And thus my friend, formerly so entrenched in pessimism, 
came to share my optimistic view of life. The discussions 
that we had had for so many years ended in complete agree- 
ment. " However," said he, " to understand the value of 
life, one must have lived long ; otherwise one is in the posi- 
tion of a man blind from his birth to whom are recounted 
the beauties of colours." In a word, my friend towards the 
end of his life changed from abject pessimism to complete 

Such a transformation or evolution cannot be regarded 
as unusual. In The Nature of Man, I showed that most 
of the great pessimistic writers had been young men. 


Such were Buddha. Byron, Leopardi, Schopenhauer, Hart- 
mann, and Mailaender, and there might be added many 
other names of less well known men. 

The question has often been asked why Schopenhauer, 
who was certainly sincere in his philosophy and who ex- 
tolled Nirvana as the perfect state, came to have a strong 
attachment to life, instead of putting it to a premature end 
as was done later on by Mailaender. The reason was that 
the philosopher of Frankfort lived long enough to acquire 
a strong instinct of life. M. Moebius, 1 a well-known autho- 
rity on madness, has made a close investigation of Schopen- 
hauer's biography, and has established the fact that towards 
the end of his life his views were tinged with optimistic 
colours. On his seventieth anniversary, he took pleasure in 
the consoling idea of the Hindoo Oupanischad and of 
Flourens that the span of man's life might reach a century. 
As Moebius put it, " Schopenhauer as an old man enjoyed 
life and was no longer a pessimist " (p. 94). Not long 
before his death he still hoped to survive yet another 
twenty years. It is true that Schopenhauer never 
recanted his early pessimistic writings, but that was 
probably because he did not fully realise his own mental 

In looking through the work of modern psychologists, I 
cannot find recognition of the cycle of evolution of the 
human mind. In Kowalevsky's able and conscientious 
study of pessimism, I was specially struck by one phrase. 
" Evils such as hunger, disease, and death are equally ter- 
rible at all stages of life and in every rank of society" 
(p- 95) said that author. I notice here a failure to recog- 
nise the modification of the emotions in the course of life 
which, none the less, is one of the great facts of human 
1 Ueber Schopenhauer, Leipzig, 1899. 


nature. Fear of death is by no means equally great at 
all stages of life. A child is ignorant of death and has 
no conscious aversion from it. The youth and the young 
man know that death is a terrible thing, but they have not 
the horror of it that comes to a mature man in whom the 
instinct of life has become fully developed. And we see 
that young men are careless of the laws of hygiene, whilst 
old men devote to them sedulous attention. This differ- 
ence is probably a notable cause of pessimism in young 
men. In his studies of the mind, Moebius : has stated his 
view that pessimism is a phase of youth which is succeeded 
by a serener spirit. " One may remain a pessimist in 
theory," he says, " but actually to be one, it is necessary 
to be young. As years increase, a man clings more firmly 
to life." " When an old man is free from melancholia, he 
is not a pessimist at heart." "We cannot yet explain 
clearly the psychology of the pessimism of the young, but 
at least we can lay down the proposition that it is a disease 
of youth" (p. 182). 

The cases of Schopenhauer and of the man of science 
whose psychical history I have sketched fully confirm the 
view of the alienist of Leipzig. 

The conception that there is an evolution of the instinct 
of life in the course of the development of a human being 
is the true foundation of optimistic philosophy. It is so 
important that it should L? examined with the minutest 
care. Our senses are capable of great cultivation. Artists 
develop the sense of colour far beyond the point attained by 
ordinary men, and distinguish shades that others do not 
notice. Hearing, taste, and smell also can be educated. 
Wine tasters have an appreciation of wine much more acute 
than that of other men. A friend of mine, who does not 
1 Moebius, Goethe, vol. i, Leipzig, 1903. 


drink wine, can distinguish burgundy from claret only by 
the shapes of the bottles, but is devoted to tea and has a 
very fine palate for different blends. I do not know if a 
good palate is a natural gift, but however this may be, it is 
certain that the palate can be brought to a high condition 
of perfection. 

The development of the senses is specially notable in 
the case of the blind in whom other powers become ex- 
tremely acute. As I thought that investigation of the 
educability of other senses in blind persons very important 
from the point of view of the development of the sense of 
life, I have tried to obtain the best available information 
on the question. The perfection of touch in the blind is 
accepted so generally as a truth that one would have ex- 
pected to find convincing facts in its favour. However, it 
is not true. Griesbach, 1 using a well-known method for 
estimating tactile discrimination, found that the sense of 
touch is not more acute in the blind than in normal persons. 
Blind persons distinguished the points of a pair of com- 
passes as separate, only when they were at least as far apart 
as in case of normal persons. Dr. Javal, 2 a well-known 
oculist who himself became blind, stated his surprise at find- 
ing that " tactile discrimination is quite notably less acute in 
the case of the blind than in the case of those with unimpaired 
vision. For instance, the index finger of a blind man who 
was a great reader got separate sensations from the points 
of a pair of compasses only when these were three milli- 
metres apart, whilst a man with normal sight had the 
double sensation at a distance of two millimetres " (p. 123). 
Griesbach goes still farther, stating that neither hearing 

1 V. Kunz, " Zur Blindenphysiologie," Wiener medicin. Wochenschrift, 
1902, No. 21. 
Physiologic de la Lecture et de fcriture, Paris, 1905. 



nor smell is better developed in the blind than amongst 
normal people. Although these senses may come to re- 
place to a certain extent the sense of sight, this occurs 
merely because the blind person uses impressions which 
the clear-sighted person hardly notices. As we see what 
is going on around us, we do not concentrate our attention 
on the different sounds and smells or other such pheno- 
mena. The blind person, on the other hand, not being 
absorbed by impressions of sight, gives attention to the 
others. Such and such a sound tells him that the garden 
gate of his neighbour has been opened to let out a carriage 
which he must avoid. A particular smell lets him recog- 
nise the place where he is, as stable or kitchen. 

From the prese'nt point of view, it is not exactly the 
acuteness of the senses which is most important. The 
acuteness might be equal in a blind person and in a normal 
person. It might even be greater in the latter, and yet it 
is only the blind person who can decipher without difficulty 
raised points so as to understand their meaning as well as 
when a normal person reads a printed book. This power 
of the blind person is developed only after a long period 
of learning, and depends on the appreciation of very deli- 
cate tactile impressions. I must point out, moreover, that 
the method of deciding by means of a pair of compasses 
gives information only with regard to one side of the tactile 

However, although we admit that blind people do not 
really gain anything in the four remaining senses, there 
is developed in them a special kind of sensibility, which is 
spoken of in their case as a sixth sense, the "sense of 
obstacles." Blind people, especially those who have lost 
their sight in youth, acquire a surprising habit of avoiding 
obstacles and of recognising at a distance objects round 


about them. Blind children, for instance, can play 'in a 
garden, without knocking themselves against the trees. 

Dr. Javal 1 states that some blind people, when passing in 
front of a house, can count the ground floor windows. A 
professor, who had been blind from the age of four years, 
could walk in the garden without striking against a tree 
or post. He appreciated a wall at a distance of two metres 
from it. One day, going for the first time into a large 
apartment, he recognised the presence of a big piece of 
furniture in the middle, which he took to be a billiard table. 

Another blind man, walking in the street, could distin- 
guish houses from shops and could count the number of 
doors and windows. The existence of this sense of ob- 
stacles rests upon so many exact facts that it is indubitable. 
The opinions as to the mechanism by which it operates, 
however, are very varied. Dr. Zell 2 thinks that it is not 
a sense peculiar to blind people and "that those of normal 
sight could equally well acquire it by practice, because it 
exists in nearly everyone without being noticed." None 
the less, there are some blind people who, even in the course 
of years, do not acquire it. M. Javal, for instance, learnt 
to read with his fingers extremely well, but was never able 
to distinguish obstacles at a distance. 

The most probable hypothesis refers this sixth sense to 
the action of the tympanic membrane and the auditory 
apparatus. It is known that loud noise makes it more 
difficult to perceive obstacles, and snow, by dulling the 
sound of steps, has a precisely similar effect. Blind tuners, 
in whom the sense of hearing is well developed, have the 
sixth sense very marked. 

The examples I have given show that the human body 
possesses senses which come into operation only in special 

1 Entre aveugles, Paris, 1903. 2 Der Blindenfreund^ Feb. i5th, 1906. 

S 2 


conditions, and which require a special education. The 
"sense of life" to a certain extent comes within this 
category. In some persons it develops very imperfectly, 
generally revealing itself only late in life, but some- 
times a disease or the danger of losing life stimulates its 
earlier development. Occasionally in persons who have 
tried to commit suicide, a strong instinct of life wakens 
suddenly, and impels them to make frantic efforts to escape. 

It happens, therefore, that the sense of life develops 
sometimes in healthy people, sometimes in those who suffer 
from acute or chronic disease. These variations are parallel 
with the development of the sexual instinct, which in some 
women is completely absent and in others develops only 
very late. In certain cases, it is awakened only by special 
conditions, such as child-birth, or even some defect of 

As the sense of life can be developed, special pains ought 
to be taken with it, just as with the making perfect of the 
other senses in the blind. Young people who are inclined 
to pessimism ought to be informed that their condition of 
mind is only temporary, and that according to the laws of 
human nature it will later on be replaced by optimism. 




Goethe's youth Pessimism of youth Werther Tendency 
to suicide Work and love Goethe's conception of life in 
his maturity 

THERE can be drawn from analysis of the lives of great men 
information that is very important in the study of the con- 
stitution of man. I have chosen Goethe for several 
reasons. He was a man of genius distinguished by the 
comprehensive character of his ability. He was a poet and 
dramatist of the highest rank, his mind was stored with 
the most varied knowledge, and he contributed to the ad- 
vancement of natural science. As minister of state and as 
the director of a theatre, he was occupied with practical 
affairs. He reached the age of eighty-three years, and he 
passed through the phases of life in relatively normal 
circumstances ; in his many writings there are most valuable 
facts which throw a keen light on his life and nature. The 
Goethe cult in Germany has brought about the existence 
of fuller biographical details than exist regarding any other 
great man. He aspired to lead "the higher life," and, 
throughout his existence, he occupied himself with the 
most serious problems of humanity. 

It is not surprising that Goethe became a subject of 


investigation for me, but as the main facts as to his history 
are widely known I need not elaborate them here. 

Goethe was reared in circumstances that were favourable 
in every respect, and from his earliest years showed re- 
markable traits. As his memory was good and his ima- 
gination vast, the study of ancient and modern languages 
and the routine curriculum of a classical education were 
little more than an amusement to him. The rich library 
of his father placed all sorts of books at his disposal, and 
whilst he was still young he devoted himself to reading 
with the enthusiasm and passion that were the chief quali- 
ties of his character. When he was fifteen years old he 
began to write verses, although he was still unconscious 
of his destiny as a poet. He intended to be a learned man, 
and looked forward to the career of a professor. 

At the age of sixteen, he entered the University of Leip- 
zig with the intention of studying natural science seriously. 
Law and philosophy interested him but little; he turned to 
natural science and medicine, although his actual study 
was rather superficial. His disposition was lively and rest- 
less; he made many friends, frequented the theatre and 
plunged into all kinds of gaiety. Extracts from letters he 
wrote during this period show the kind of life he led. 
When he was a student, eighteen years old, he wrote to a 
friend, " And so good-night; I am drunk as a hog." A 
month later, to the same friend, he summed up his life as 
a "delirium in the arms of Jetty." 

He graduated in law at Strassburg, and became a 
barrister, but realising that such a career was unsuitable, 
he became a man of letters, encouraged by the success of 
his first literary efforts. 

From the point of view of a writer, he sought all kinds of 
experiences. He devoted himself to literature and science, 


including even the occult sciences, and frequented the 
theatre and society. He was specially attracted by the 
imaginative side and gave little thought to the problems of 
science. " I must have movement," he wrote in one of 
his note-books. 

When he was young, his temper was violent and he fell 
into fits of passionate rage. His contemporaries have re- 
lated that when he was in such a condition he would destroy 
the illustrations and tear up the books on his work-table. 
These experiences have been vividly described in his 
famous romance, The Sorrows of Werther. I shall give 
a few extracts to show the exact state of mind of the young 
pessimist. "It is the fate of some men not to be under- 
stood." " Human life is a dream ; I am not the first to say 
that, but the idea haunts me. When I reflect on the narrow 
limits which circumscribe the powers of man, his activities 
and intelligence; when I see how we exhaust our forces in 
satisfying our wants and that these wants are for no more 
than the prolongation of a miserable existence; that our 
acquiescence in so much is merely resignation engendered 
by dreams, like that of a prisoner who has covered the 
walls of his cell with pictures and new landscapes; such 
things, my friend, plunge me into silence." "Our learned 
teachers all agree that children do not know why they have 
desires; but that grown men should move on the earth 
like children, and, like these, be ignorant whence they have 
come and whither they go, like these strive little for real 
things, but be ruled by cakes and sweets and rods; no one 
will believe such things, though their truth is patent. I 
admit readily (for I know what you will say) that they ape 
the happiest men who live from day to day like children, 
who play with their dolls, dress them and undress them, 
who reverence the cupboard where mamma keeps the 


gingerbread, and who, when they have got what they wish, 
cry, with their mouths full, ' How happy we are ! ' ' 

Werther proclaimed his pessimism before his romance 
with Charlotte, and it was his view of life that made his 
love-affair turn out unhappily. But the fame of Goethe's 
Werther was due, not to the tragic fate of the young lover, 
but to the general views which were in harmony with the 
conception of the world held by the best minds of the time. 
Byronism was born before Byron. 

Werther affords a good illustration of the disharmonies 
in the development of man's psychical nature. Inclination 
and desires develop extremely strongly and before will. 
Just as in the development of the reproductive functions, 
as I showed in The Nature of Man, the different factors 
develop unequally and unharmoniously, so there is in- 
equality and disharmony in the order of the appearance of 
the higher psychical faculties. Sexual appreciation and a 
vague attraction to the other sex appear at a time when 
there can be no possibility of the normal physical side of 
sex, with the result that many evils come about in the long 
period of youth. The precocious development of sensi- 
bility brings about a kind of diffused hyperaesthesia which 
may lead to trouble. The infant wishes to lay hold of 
everything he sees before him ; he stretches out his arms to 
grasp the moon and suffers from his inability to gratify his 
desires. In youth there is still well-marked disharmony. 
Young people cannot realise the true relations of things, and 
formulate their desires before they understand that their will- 
power is not strong enough to gratify them, as will is the 
latest of the human powers to develop. 

Werther fell in love with a kindred spirit and gave way 
to his passion without consideration of the difficulties, 
Charlotte being already betrothed to another. This is the 


plot of the tragedy of the young man, who committed 1 
suicide, having given way to pessimism. He had not the 
will-power to conquer his sentiments and so fell into a state 
of lassitude, until, weary of life, he could see no other end 
than to blow out his brains. 

I need not linger over the last phase of the story of 
Werther, for it is the character of Goethe himself that is of 
interest. Goethe was able to subdue his passion for Lotte, 
and, after many amorous woes, consoled himself with 
another woman. Notwithstanding this difference, it is cer- 
tain that in Werther, Goethe was telling part of the story 
of his own youth. Goethe himself is a witness to this, for 
in a letter to Kestner he wrote that " he was at work on the 
artistic reproduction of his own case." The letter was 
written in July, 1773, whilst Goethe, then a writer twenty- 
four years old, was relating the sorrows of young Werther. 

The general tendency of Werther has been described 
excellently by Carlyle. 1 " Werther," he wrote, " is but the 
cry of that dim, rooted pain, under which all thoughtful 
men of a certain age were languishing ; it paints the misery, 
it passionately utters the complaint ; and heart and voice, 
all over Europe, loudly and at once responded to it." 
Werther was " the first thrilling peal of that impassioned 
dirge which, in country after country, men's ears have lis- 
tened to, till they were deaf to all else." 

In the pessimistic period of his life, Goethe often cherished 
the idea of suicide. In his biography he relates that at this 
time he used to have, by his bedside, a poisoned dagger, 
and that he had repeatedly tried to plunge it in his bosom. 
Of these times he wrote to his friend Zelter 2 "I kno"w 

1 Critical and Miscellaneous Essays, vol. i, pp. 164-5, ' n ^ e Essay on 

2 Briefwechsel zwischen Goethe und Zelter. Letter of Dec. 3, 1812. 


what it has cost me in effort to resist the waves of death." 
The suicide which was the subject .of the end of his romance 
made a deep impression upon him. Although he overcame 
his passion for Charlotte, his view of life remained tinged 
with pessimism for many years; in a note-book of 1773, for 
instance, he wrote " I am not made for this world." 1 These 
words are the more striking as they date from a period when 
exact ideas regarding the adaptation of the organism and 
the character to the environment did not exist. Goethe, 
with his too delicate sensibility, felt himself out of harmony 
w'ith his environment. 

It is very interesting to trace Goethe's subsequent de- 
velopment and the transformation of a youthful pessimist 
into a convinced optimist. Goethe found a remedy for his 
crises of grief in work, poetical creation and love. He 
declared that the mere describing his woes on paper brought 
assuagement. The tears that they shed console women and 
children ; and the poetry in which he expresses his suffer- 
ing consoles the poet. Goethe's romance w r ith Charlotte 
was not quite at an end when he found himself ready to 
love her sister Helen. He wrote to Kestner in December, 
1772: "I was about to ask you if Helen had arrived, 
when I got the letter telling me of her return." " To judge 
from her portrait she must be charming, even more charm- 
ing than Charlotte. Well, I am free and I am thirsting 
for love." " I am here at Frankfort again with new plans 
and new dreams, and all will be well if I find someone to 
love." Soon afterwards, in another letter to Kestner, he 
wrote: "Tell Charlotte that I have found here a girl 
whom I love with all my heart; if I wanted to marry, I 
should choose her before anyone else." 

As he had not yet realised his true vocation, Goethe 
became a court minister at Weimar. He devoted himself 
1 Quoted in Moebius' Goethe, vol. ii, p. 80. 


to his duties with an enthusiasm that carried him far beyond 
the usual affairs of state. He wished to deepen his know- 
ledge of such administrative problems as the construction 
of roads and the management of mines, and he studied 
geology and mineralogy with a real zest. Forest adminis- 
tration and agriculture led him seriously into botany, and as 
he had the direction of a school of design, he thought it 
necessary to learn anatomy. Such varied work gave him 
a real taste for science. It was no longer the superficial 
interest that characterised his work at Leipzig and Strass- 
burg but a true devotion which led him to important dis- 
coveries, some of which have become classic. 

Even such varied occupations did not absorb his pro- 
digious genius. In his leisure he wrote poetry and prose. 
Engrossed in so much work, he was happy. His discovery 
of the human intermaxillary bone suffused him with joy. 
His intense activity was strengthened by his love for 
Madame von Stein, a love that he declared was " a life-belt 
supporting* him in the sea." A few hours with her in the 
evenings set free his soul. 

The powerful influence of love on the life of Goethe was 
specially prominent in this period when he was passing 
from pessimistic youth to optimistic maturity. Being 
forced to separate from Madame von Stein, he gave way to 
grief that plunged him again in the worst hours of his life. 
At the age of thirty-seven he fell back into a crisis like that 
of the days of Werther. "I have discovered," he said in 
1786, " that the author of Werther would have done well to 
blow out his brains when he had finished his work." Soon 
afterwards he wrote that "death would have been better 
than the last years of his life." 

This relapse into pessimism was shorter and less acute 
than his first experience. He began to find that frequently 
his delight in existence and sense of life were proved by his 


fear of death. When he was little more than thirty years 
old, he began to take precautions against the chance of his 
death. He wrote to Lavater : " I have no time to lose; 
I am already getting on in years, and it may be that fate 
will destroy me in the midst of my life." On all sides his 
wish to live and his shrinking from death reveal themselves. 
It was at this time, a few days after his thirty-first birthday, 
that he wrote those famous lines, counted amongst the 
finest of his poetry, on the summit of the Gickelhahn, on 
the wall of a small room, and which end with the presenti- 
ment of his own death, " Before long, you also will be at 

The crisis through which he passed at the age of thirty- 
seven, as the immediate result of his separation from 
Madame von Stein, but perhaps also partly due to brain 
fatigue, brought about his sudden departure from Weimar 
and his long sojourn in Italy. There he came to life again, 
and everything interested him, archaeology, art and nature. 
The joy of life came back to him, and he soon consoled him- 
self for the lost love of the blue-stocking Baroness in the 
arms of a pretty, blue-eyed girl of Milan. This girl, whose 
name was MaddalenaRiggi, like Charlotte, was already be- 
trothed, a circumstance, however, that had a different result. 
Even after she had given up the man to whom she had been 
engaged, Goethe avoided any permanent bond and soon 
abandoned her definitely. He chose to associate with 
Faustine, another Italian girl, with whom he lived during 
the last period of his stay at Rome. This affair, which was 
less ideal and much simpler than his love for Madame von 
Stein, he has described in his Roman Elegies, which throw 
a vivid light on his temperament. I shall give some char- 
acteristic extracts. 

" A sacred enthusiasm inspires me on this classic soil ; 
the old world and the world around me raise their voices 


and draw me to them. Here I follow the ideas and turn 
over the pages of the ancient writers, giving myself no rest 
whilst day lasts and ever reaching new delights. By night 
love calls me to other cares ; and if I am only half a philo- 
sopher, I am twice happy. But may I not say that I am 
also learning when my eye follows the contours of a loving 
breast, when with my hand I trace the lines of her form ? 
It is then that I understand marble, I think and compare, I 
see with an eye that touches and touch with a hand that 
sees." "Often I have made verses in her arms; often my 
playful finger has softly beaten out my hexameters on her 
back. As she breathes in her sweet sleep, her breath burns 
me to my innermost soul." 1 

His stay in Italy brought Goethe definitely to maturity. 
On this important stage in his life let us hear his bio- 
grapher, Bielschowsky. " The voyage to Italy made a 
new man of him. His sickliness and nervousness dis- 
appeared. The melancholy which led him to think of early 
death and made him regard death as better than the former 
conditions of his life was replaced by a sublime serenity 
and joy in living. The taciturn and preoccupied man who 
in no society abandoned his grave thoughts had become 
happy as a child " (vol. i, p. 412). " From this time on, 
in calm and enviable security, he passed through the cycle 
of life which seemed so mysterious to others. Goethe 
became the serene Olympian, the wonder of posterity, 
whilst many of his contemporaries no longer saw in him 
the passionate pilgrim " (ibid., p. 417). 

It was after reaching the age of forty years that Goethe 
entered on the optimistic phase of his life. fr 

1 The Fifth Roman Elegy, Blaze's French translation, 1873 p. 186. 
Some of Goethe's biographers, and amongst them G. H. Lewes, maintain 
that these lines relate to Christine, Goethe's xvife. This is erroneous ; 
they refer to Faustine (see Bielschowsky, i, p. 517). 



Goethe's optimistic period His mode of life in that period 
Influence of love in artistic production Inclinations towards 
the arts must be regarded as secondary sexual characters 
Senile love of Goethe Relation between genius and the 
sexual activities 

THE moral equilibrium of the great writer was not estab- 
lished once for all. In the course of his life, Goethe had 
several relapses into pessimism which, however, were ephe- 
meral, and after which he became a man as complete and 
harmonious as was possible in the circumstances of his life. 
He reached a serene old age, and his activity did not relax 
until after his eightieth year, when he died. 

As I have already said, Goethe realised the value of life 
in good time. Having become an optimist, he experienced 
the joy of existence and coveted as much of it as possible. 
When he was an old man, he declared that life, like the 
Sibylline books, became more valuable the fewer of them 
were left. There appeared in him a normal phase of human 
nature. The conditions under which he lived, however, 
were far from ideal. His health was indifferent. In his 
youth he suffered from severe haemorrhage, probably tuber- 
culous, and throughout his life he was subject to various 
more or less serious maladies, such as gout, colic, nephritis, 
and intestinal troubles. His habits were unwholesome. He 


was brought up in a region of vineyards, and in his youth 
he acquired the habit of drinking wine in quantities cer- 
tainly harmful. This he himself realised, and when he was 
thirty-one years old, after he had acquired the instinct of 
life, he gave it serious attention. " I wish I could abstain 
from wine," he wrote in his note-book. Some weeks later 
he wrote, " I now drink almost no wine." x 

But he had not the strength of character to remain tem- 
perate, and soon after his decision, he had fits of bleeding 
at the nose, which he attributed to " having taken some 
glasses of wine." 2 To his last day, he took wine regularly, 
and sometimes to excess. J. H. Wolff, who dined with him 
at Weimar, when he was in his eightieth year, was sur- 
prised by his appetite and by the quantity of wine he 
drank. "In addition to other food, he ate an enormous 
portion of roast goose, and drank a bottle of red wine." 3 
In Eckermann's interesting narrative of the last ten years 
of Goethe's life (1822 1832) there is repeated mention of 
wine. Goethe seized every occasion to drink it. Some- 
times it was the visit of a stranger, sometimes a present of 
some famous vintage. It was said that he drank from one 
to two bottles of wine daily (Moebius). None the less, he 
was convinced that wine was not good for intellectual work. 
He had remarked that when his friend Schiller had drunk 
more than usual, to increase his strength and stimulate his 
literary activity, the result was deplorable. He said to 
Eckermann (March 11, 1828), "He will ruin his health 
and will spoil his work. That is why he has made the 
faults the critics have pointed out." In another conversa- 
tion (March u, 1828) he stated that what was written 

1 Moebius' Goethe, vol. ii, pp. 84-87. 

2 Moebius' Goethe, vol. ii, pp. 84-87. 

3 Quoted by Bode in Goethe's Lebenskunst, Berlin, 1905, p. 59. 


under the influence of wine was abnormal and forced, and 
ought to be deleted. 

Love was the great stimulus of Goethe's genius. The 
love affairs, the histories of which fill his biography, are 
well known. Many have been shocked by them; others 
have tried to justify them. It has been suggested that his 
disposition made it necessary for him to impart his ideas 
and obtain sympathy for them, and that his love for women 
was the expression of a purely artistic feeling and had 
nothing in common with the ordinary passion. 

The truth is that artistic genius and perhaps all kinds of 
genius are closely associated with sexual activity. I agree 
with the proposition formulated by Dr. Moebius 1 that 
"artistic proclivities are probably to be regarded as 
secondary sexual characters." Just as the beard and some 
other male characters are developed as means of attracting 
the female sex, so also bodily strength, strong voice and 
many of the talents must be regarded as due to the need to 
fulfil the sexual relations. In primitive conditions woman 
worked more than man ; man's superior force served him 
principally in fighting with other males, the object of the 
combats usually being possession of a woman. Just as a 
victorious combatant covets the presence of a woman as 
witness of his prowess, so an orator speaks better in the 
presence of a woman to whom he is devoted. Singers and 
poets are stimulated in their arts by the love they awaken. 
Poetic genius is intimately associated with sexual power 
and castration inhibits it. Just as castrated animals retain 
their physical strength, but become changed in character, 
losing in particular their combative nature, so a man of 
genius loses much of his quality with the sexual function. 
Amongst the eunuchs on record, Abelard is the only poet, 
1 Ueber die Wirkungen d. Castration, Halle, 1903, p. 82. 


but Abelard was forty years old when he ceased to be a 
man, and at the same time he ceased to be a poet. Many 
singers have been eunuchs, but they have been merely 
executants, and have taken no part in musical creation. 
Some musical composers have been eunuchs, but these 
were of mediocre ability and their names have been for- 
gotten. When castration has taken place at an early age, 
it has a much more powerful influence in modifying the 
secondary sexual characters. 

From the point of view of a naturalist, I cannot agree 
with the moralists who have blamed Goethe for his sexu- 
ality, nor do I share the views of those defenders of him 
who have wished to deny the facts or to explain them away 
by the suggestion that they did not relate to sexual love. 

Extracts from the Roman Elegies show quite clearly 
what was the nature of Goethe's love affairs. His feelings 
towards the Baroness von Stein have been taken as reveal- 
ing merely idealistic love. But some of his letters to her 
are clear evidence that their relations were erotic (Moebiirs, 
Goethe, vol. ii, p. 89). The love which he bore for 
Minna Herzlieb, the girl who inspired him to write Elec- 
tive Affinities (Wahlverivandschaften), has been described 
by Goethe himself in a poem so crudely erotic that it has 
been impossible to publish it (Lewes, vol. ii, p. 314). 

A fact to which I specially desire to call attention is that 
Goethe's amorous temperament survived until the end of 
his life, and all the world has been astonished by the vigour 
of his poetic genius in extreme old age. 

Goethe has been the subject of derision because at the 
age of seventy-four years he fell deeply in love with UlriquQ. 
de Lewetzow, who was quite a young girl. This incident, 
however, merits close attention as it is a typical case of 
senile love in a man of genius. 



Whilst he was at Carlsbad, Goethe became acquainted 
with a pretty girl seventeen years old, with beautiful blue 
eyes, brown hair, and of an ardent, good-humoured and 
happy disposition. In the first two seasons nothing in 
particular happened. But in the third summer, at Marien- 
bad, Goethe became passionately enamoured of Ulrique, 
who was then nineteen years old and in the full bloom of 
her young womanhood. His love made him young again; 
he passed long hours with her and took to dancing with 
her. " I am quite certain," he wrote to his son, "that it 
is many years since I have enjoyed such health of body 
and mind" (Aug. 30, 1823). His passion became so 
serious that the Grand Duke of Saxe- Weimar, on behalf 
of his friend, made a formal proposal of marriage for 
Mademoiselle de Lewetzow. The mother gave an evasive 
answer, and the matter rested in suspense for long, and 
ended in a refusal. Goethe withdrew to his family, but 
encountered there strong opposition to his project of 

This misadventure troubled the old poet so seriously that 
he fell ill. He suffered from pain in the region of the heart 
and from profound mental disturbance. He complained to 
Eckermann " that he could do nothing, that he could get to 
work on nothing, and that his mind had lost its power." 
" I can no longer work," he said. " I cannot even read, 
and it is only in rare and fortunate moments that I can 
think, feeling myself partially soothed " (Eckermann, Nov. 
16, 1823). Eckermann makes the following reflection on 
the state of mind of the great old man. "His trouble 
seems to be not merely physical. The passionate desire 
which he acquired for a young lady at Marienbad this 
summer, and against which he is still struggling, must be 
regarded as the chief cause of his illness " (Nov. 17, 1823). 


As in all earlier crises, Goethe sought consolation in 
poetry and love. He left Marienbad in a carriage and 
began to set down verses astonishingly vigorous for so old 
a man. His Marienbad elegy is held to be one of the best 
of his poetical achievements. The following extracts will 
give an idea of his state of mind at that period. 

" I am lost in unconquerable desire; there is nothing left 
but everlasting tears. Let them flow, let them flow unceas- 
ingly. But they can never extinguish the fire that burns 
me. My heart rages; it is torn in pieces, this heart where 
life and death meet in a horrible combat." "I have lost 
the universe, I have lost myself, I who until now have been 
the favourite of the gods ; they have put me to the question, 
they offered me Pandora, rich in treasure and still richer in 
perilous seductions ; they made me drunken with the kisses 
of her mouth, which gave me its sweets; they have torn 
me from her arms, and have struck me with death." 

Goethe concealed his elegy for some time, guarding it as 
something sacred, but eventually handed it over to Ecker- 
mann. Poetic creation soothed his mind only for a time. 
His nature demanded some more efficacious consolation. A 
few weeks after the separation he began to complain bitterly 
of the absence of the Countess Julie von Egloffstein, whom 
he wanted very much. "She cannot know what she is 
keeping from me and what she makes me lose, nor can 
she know how I love her and how she engrosses my 
mind." He derived a little comfort from the visits of 
Madame Szymanowska, whom he admired "not only as a 
great artist, but as a pretty woman " (Eckermann, Nov. 3, 
1823). " I am deeply grateful to this charming woman," 
he said to the chancellor, " for her beauty, her sweetness, 
and her art have soothed my passionate heart " (Bode, p. 
151). He also renewed his relations with Marianne Jung, 


the retired actress and dancer. "When Goethe had to 
turn his thoughts from Ulrique, the image of the pretty 
owner of Gerbermuhle again occupied his mind. A visit 
to her, and intimate correspondence with her, restored peace 
to his heart so greedy of love" (Bielschowsky, vol. ii, 
p. 487). 

His devotion to Ulrique was Goethe's last acute attack of 
love ; but until the end of his days he felt the need of being 
surrounded by pretty women. As director of the theatre, 
he came in contact with many young women who wished 
engagements. He confessed to Eckermann that he required 
much strength of mind to resist feminine charms which 
tempted him to be unjustly favourable to the prettiest of 
those who sought employment. " If I allowed myself to 
fall into an intrigue of gallantry, I would become like a de- 
magnetised needle as soon as the girl found a real lover " 
(Eckermann, March 22, 1825). 

His daughter-in-law's sister has related that Goethe liked 
to have young girls in his study whilst he was at work. 
They had to sit quietly, neither working nor talking, often 
a difficult task for them (Bode, p. 155). 

Even on the last day of his life, whilst in delirium, he 
cried out, "What a pretty woman's head with black curls 
on a black ground " (Lewes, vol. ii, p. 372). After utter- 
ing several other more or less incoherent phrases, he drew 
his last breath. 

The facts which I described in the chapter of this book 
dealing with old age have made clear how long 
sexuality persists in men. As the testes resist atrophy 
better than other organs, and even in extreme old age still 
form active spermatozoa, it is natural that their condition 
should be reflected on the organism generally, and that feel- 
ings of love should still be excited. If by some accident 


Goethe had become a eunuch early in life, he would have 
been a different being. The moralists who have been 
shocked by his amorous intrigues would have been satis- 
fied, but the world would have lost a great poet. More- 
over, Goethe is no exceptional case amongst writers. The 
temperament of Victor Hugo and his devotion to women up 
to the end of his days are well known. More recently, after 
the death of Ibsen, a profound sensation was made by the 
revelation of his love for Mademoiselle Bardach, who in- 
spired his genius during the last period of his life. 

Not only poetic creation but other forms of genius are 
intimately associated with the sexual function. The philo- 
sopher Schopenhauer, who was no ascetic, wrote as follows, 
at the age of twenty-five, when he was in full creative 
activity, " In the days and at the hours when the voluptu- 
ous instinct is strongest, when it is a burning covetousness, 
it is then that the greatest forces of the mind and the greatest 
stores of knowledge are ready for the most intense activity." 
"At such moments life is truly at its strongest and most 
active, for its two poles are then operating most actively ; 
and this is plain in the man of the highest intelligence. In 
these hours one sees more than in years of passivity " 
(quoted in Moebius' Schopenhauer, p. 55). " This means 
that in Schopenhauer intellectual creation was linked with 
erotic excitement " (ibid., p. 57). 

It was facts of such a nature that led Brown-Sequard to 
his idea of strengthening cerebral activity by injections of 
the substance of testes. To obtain the same effect, he pre- 
scribed another means, the value of which was proved in 
the case of two individuals aged from forty-five to fifty 
years, the observations being continued over several years. 
"By my advice," he said, "when these had to perform 
any great physical or intellectual work, they got themselves 


into a condition of sexual excitement." " The testes being 
in this way thrown into functional activity, there was soon 
produced the desired increase in the power of the nerve 
centres." 1 

Although I insist on the existence of a close relation 
between intellectual activity and the sexual function, I do 
not mean to assert that there have not existed exceptions 
to the rule. 

Now that I have described certain important factors in 
the genius of Goethe, I shall pass on to a study of his state 
of mind in the last period of his life, the splendour and 
harmony of which have been so often admired. 

1 Comptes rendus de la Socitte de Biologic, 1889, p. 420. 



Old age of Goethe Physical and intellectual vigour of the 
old man Optimistic conception of life Happiness in life 
in his last period 

DRINKERS of wine may take the case of Goethe as an argu- 
ment against temperance. Although he was not healthy in 
his youth, his large consumption of wine did not prevent 
him from enjoying an old age full of force and intellectual 
work. Eckermann, who was his intimate and constant 
companion in the last ten years of his life, was never weary 
of expressing his surprise and delight at the physical and 
moral vigour of the distinguished old man. He found 
Goethe on his return to Jena, at the age of seventy-four, in a 
condition " very pleasant to see ; he was in good health and 
robust, so that he could walk for hours " (Sept. 15, 1823). 
His eyes were "brilliant and clear and his whole expres- 
sion was that of joy, vigour and youth" (Oct. 29). In 
walks with Eckermann, Goethe forced the pace and showed 
strength which rilled his companion with delight (March, 
1824). His voice was full of character and of force (March 
30, 1824), and every word showed his vitality (July 9, 

In a conversation that Eckermann had with Goethe when 
the latter was seventy-nine years old " the sound of his 
voice and the fire in his eyes were of such strength as would 


have been normal in the full flush of youth" (Mar. 11, 
1828). Such characters were preserved until the end of the 
life of the great man, and a few months before his death 
Eckermann jotted in his book that he saw him every day in 
full vigour and freshness, looking as if his health might be 
prolonged indefinitely (Dec. 21, 1831). In the beginning of 
the following spring, Goethe caught a feverish cold, pos- 
sibly pneumonic, and died, probably from weakness of the 
heart. His illness lasted a week. If he had not been a 
drinker of wine he would have been able to withstand this 
attack and to live still longer. 

The intellectual vigour of Goethe was even greater and 
more remarkable than his physical strength. His interests 
were extremely wide, and his thirst for knowledge was 
never appeased. Once, when he was absorbed by the in- 
terest of hearing d'Alton describe in detail the skeleton of 
rodents, Eckermann states his surprise that a man not far 
short of eighty years old " did not give up seeking for and 
gaining knowledge." But in these matters he never lost his 
interest. He wished always to go further and further, 
always to learn, so showing himself to be a man of eternal 
and undying youth (April 16, 1825). Goethe's aptitude for 
understanding and his memory were most unusual. When 
he was more than eighty, he surprised those who heard 
him " by the incessant flow of his ideas and by his extra- 
ordinary fertility in invention " (Oct. 7, 1828). 

" The old age of Goethe is the most striking proof of the 
extreme force of his constitution," said his medical bio- 
grapher, Dr. Moebius. Works which were written in his 
last years are for the most part beyond praise, both because 
of their finished form, and by their wisdom and feeling. 
What other man of eighty has written anything of the 
same character? From the physiological point of view I 


am more surprised at his works when he was old than at those 
of his youthful activity" (Moebius, Goethe, i, 200, 201). 

Although Goethe's character, which was fiery and intense 
in his youth, became much more calm with age, there still 
came to him moments when he was carried away. He had 
certain eccentricities of an old man, and in particular was 
often very despotic, and this trait has been the occasion of 
many stories. His temper, however, became much more 
certain in his old age, and his general conceptions much 
more optimistic. Apart from certain short crises, he was 
happy in his life. In 1828, he settled down at Dornburg 
and there passed a tranquil existence. " I stay out of 
doors nearly all day and engage in private conversations 
with the tendrils of the vine which communicate their 
excellent ideas to me, ideas about which I shall have 
marvellous things to tell you " he wrote to Eckermann on 
June 15, 1828 " I am composing verses which are quite 
good, and I hope that it will be given to me to live long 
in this condition. I am quite contented," he said to his 
collaborator, "at the beginning of spring, when I see the 
first green leaves, I am pleased to watch how, from week 
to week, one leaf after another appears on the stem. I am 
delighted in May, when I see a flower-bud ; I feel really 
happy, when in June the rose offers to me its splendour and 
its perfume" (Eckermann, April 27, 1825). His delight 
in life at this epoch is also revealed in many letters. " I 
wish to whisper this in your ear," he wrote to Zelter on 
April 29, 1830. "I am delighted to find that even at 
my great age, ideas come to me the pursuit and de- 
velopment of which w r ould require a second life." 

His conception of life had changed enormously since the 
epoch of Werther. Goethe himself said: "When one is 
old, one thinks many things about this world quite 
different from when one was young " (Eckermann, Dec.. 


1829). The youthful sensitiveness which had brought him 
so much suffering was notably dulled. Eckermann was 
astonished at the way he accepted wounds to his pride. It 
happened that his design for the new theatre at Weimar 
was abandoned while it was being constructed, and re- 
placed by another not his own work. Eckermann was 
much disturbed by this, and went to see Goethe in a state 
of apprehension. "I was afraid," he said, "that so un- 
expected a step would profoundly wound Goethe. Well, 
there was nothing of the sort; I found him in the best of 
tempers, quite calm, absolutely above all feelings in the 
matter." When he had reached his eighty-fourth year, 
Goethe had no weariness of life. In his last illness, he 
showed not the smallest desire to die. He expected to get 
better, and thought that the approach of summer would re- 
store his strength. The desire to live was strong in him. 
None the less, he recognised that his cycle of life was 
finished, and although he had no weariness of life, he felt a 
kind of satisfaction that life was over. " When, like me, a 
man has lived eighty years," he said, "he has hardly the 
right to live, but ought to be ready every day to die, and to 
think of putting his house in order" (Eckermann, May 
i5> 1831). None the less, he continued his work, in par- 
ticular revising the last two chapters of the second part of 
Faust. When he had finished them, Goethe was extremely 
pleased. "I can consider," he said, "any days which 
come to me yet as a real gift, as it is a matter of no moment 
if I write anything more or what such work should be " 
(Eckermann, June i, 1831). 

Goethe gave Faust one hundred years of life, and it is 
probable that he thought of that period as his own span. 
Although he did not reach it, he approached it, after 
having lived a most active life, full of most valuable lessons 
for posterity. 



Faust the biography of Goethe The three monologues 
in the first Part Faust's pessimism The brain-fatigue 
which finds a remedy in love The romance with Mar- 
guerite and its unhappy ending 

" GOETHE was Faust, Faust Goethe," said the biographer 
of the great poet (Bielschowsky, vol. ii, p. 645). Most 
people admit that in Faust Goethe gave his auto- 
biography on a more detailed scale than in Werther. 
Why then should I follow my analysis of Goethe himself, 
which was based on exact facts, with an analysis of Faust ? 
I do so because in addition to the biographical details in 
Faust, there are many ideas which illuminate the poet's 
conception of life. Goethe's life explains Faust, and 
Faust explains the soul of its author. And I am con- 
vinced that an accurate study of so great a man is of high 
importance in the investigation of human nature. 

The two Parts of Faust correspond with two distinct 
periods in Goethe's life. In the first Part, Faust was pes- 
simistic, in the second optimistic. Although many of the 
high problems that occupy humanity are raised and dis- 
cussed in Faust, love is the centre on which the drama 

In the first Part, conceived and for the most part written 


during his youth, the chief theme is the love of a young 
man for a pretty and attractive girl towards whom the hero 
acts in a fashion opposed to conventional morality. As in 
most of his principal works, Goethe has made an episode in 
his own life the basis of Faust. It is the well-known 
story of Frederique, the daughter of a clergyman, for whom 
the brilliant young author conceived a violent passion and 
who returned his affection with a deeper and more enduring 
feeling. Goethe was alarmed at the possibility of definitely 
settling his future, and deserted the poor victim of love in 
an unfortunate state. Later on, he confessed to the Baroness 
von Stein that he had abandoned Frederique at a time 
when his desertion was likely to cause the death of the poor 
girl. " I had wounded to the quick," he wrote (Bielschow- 
sky, vol. i, p. 135), "the best heart in the world, and I 
had to repent of it long and almost unendurably." As an 
atonement, he made Frederique the heroine of " Goetz " 
and of " Clavigo," but not thinking these worthy of her, 
he immortalised her as the Marguerite of Faust. 

A learned doctor, skilled in all human knowledge, but 
who had found no satisfaction in his studies, found consola- 
tion in the beauty and charm of a young girl with whom 
he fell passionately in love. It will be interesting to trace 
the psychological process which induced him to leave the 
scene of his scientific studies tor the streets and resorts 
where he found Marguerite. 

Although Faust was represented as an old man, who had 
had time enough to absorb all human learning, his image 
bears the stamp of green youth. " Discontented with all 
his knowledge, he wished to know the secret entrails of the 
world, to be a witness of the centre of all activity, to unveil 
the principle of life." l These are the demands of a young 

1 The word Samen of the original is the expression of the alchemists 
for the " principle of life." 


man seeking to resolve the most intricate problems at one 
stroke. The speech in question dates from the period of 
Werther, when Goethe was twenty-five years old, and 
for that reason leaves no- very serious impression. 1 The 
second monologue, which ends with the attempt to take 
poison, is later, and is absent in the edition of 1790 (Frag- 
ment). It was revised when Goethe had reached his 
fiftieth year, and displays a riper maturity. Although 
lacking exactness, it depicts in an interesting fashion the 
miseries of life. 

Some alien substance more and more is cleaving 

To all the mind conceives of grand and fair ; 

When this world's Good is won by our achieving, 

The Better, then, is named a cheat and snare. 

The fine emotions, whence our lives we mould, 

Lie in the earthly tumult dumb and cold. 

If hopeful Fancy once, in daring flight, 

Her longings to the Infinite expanded, 

Yet now a narrow space contents her quite, 

Since Time's wild wave so many a fortune stranded. 

Care at the bottom of the heart is lurking; 

Her secret pangs in silence working, 

She, restless, rocks herself, disturbing joy and rest; 

In newer masks her face is ever drest, 

By turns as house and land, as wife and child, presented, 

As water, fire, as poison, steel ; 

We dread the blows we never feel, 

And what we never lose is yet by us lamented. 

Fear of the evils which lie in wait for us and against 
which we can make no provision render life insupportable. 
Faust's frame of mind as described in these lines recalls 
Schopenhauer, who was always afraid of something ; fear, 
sometimes of thieves, sometimes of diseases, tormented 

1 Erich Schmidt, Goethe's Faust in urspritnglicher Gestalt, 6th edit., 
Weimar, 1905, p. i. 

2 Faust, Bayard Taylor's translation. London : Warne & Co., 
pp. 20-21. 


him. He would never go to a barber's to be shaved, and 
always carried his own drinking cup with him. 

"Is it not better to end such a life, and to kill oneself, 
even if it mean annihilation?" asked Faust. He took up 
the poisoned goblet and put it to his lips, but, arrested by 
singing and the sound of bells outside, he refrained, and 
life laid hold of him. Not religious faith, however, but 
memories of childhood, "the happy sports of youth and 
the gay festivals of spring " were the agencies that recalled 
Faust to the earth. He went out of doors, mingled with 
the crowd, tried to amuse himself amongst men, and 
savoured the beauty of the new-born spring, but all these 
could not make him forget the evil of life. He met his 
pupil, talked with him, and again displayed his pessimism. 

O happy he, who still renews 
The hope, from Error's deeps to rise for ever ! 
That which one does not know, one needs to use; 
And what one knows, one uses never. 1 

Then follows the celebrated monologue of Faust over 
which so many commentators have lost their heads and 
wasted oceans of ink. 

Two souls, alas ! reside within my breast, 
And each withdraws from, and repels, its brother. 
One with tenacious organs holds in love 
And clinging lust the world in its embraces; 
The other strongly sweeps, this dust above, 
Into the high ancestral spaces. 2 

On this passage has been built up a whole theory of 
"double natures" with which has been incorporated the 
dualism of Manicheism, the two natures of Christ and what 
not besides. 3 

1 Op '/., p. 32. 

2 Op. at., pp. 33, 34. 

3 Details of this will be found in Kuno Fischer's Goethe's Faust, 
PP. 328-330. 


There exists in literature no better expression of human 
disharmony than this monologue " of the two souls." It 
portrays the unbalanced condition so frequent in youth and 
is a valuable indication of the real youth of Faust. 

On his return to his study, Faust again revealed his 

But ah ! I feel, though will thereto be stronger, 

Contentment flows from out my breast no longer. 

Why must the stream so soon run dry and fail us, 

And burning thirst again assail us? 

Therein I Ve borne so much probation ! 1 

It is at this point that Faust addresses the Spirit " that 
denies " and that is called " sin " and " evil." This spirit 
invokes before his eyes "the fairest images of dreams," 
that is to say, a woman's body in its beautiful nudity. Faust 
declares himself 

Too old to play with passion, 
Too young to be without desire. 2 

Pursued by desire 

.... when night descends, how anxiously 
Upon my couch of sleep I lay me. 
There, also, comes no rest to me; 
But some wild dream is sent to fray me. 3 

So that 

Death is desired, and Life a thing unblest. 
O fortunate, for whom, when victory glances, 
The bloody laurels on the brow he bindeth ! 
Whom, after rapid, maddening dances, 
In clasping maiden-arms he findeth ! 4 

Faust thus reached the ecstasy of passion. Soon after- 
wards in the Witches' kitchen, he saw in a mirror a 
" heavenly form " and cried : 

O lend me, Love, the swiftest of thy pinions, 
And bear me to her beauteous field. 

1 Op. tit., p. 36. 2 Op. tit., p. 45 

3 Op. tit., p. 46. * Oi>. tit., p. 46. 


A woman's form, in beauty shining! 
Can woman, then, so lovely be? 
And must I find her body, there reclining; 
Of all the heavens, the bright epitome? 
Can Earth with such a thing be mated? l 

Discontent with life, sense of the insufficiency of human 
knowledge and the most gloomy pessimism lead to the 
passion of love which, eventually, after many devious paths, 
throws Faust into the arms of Marguerite. The story is one 
of the world's great romances and everyone knows it. 
Faust all unconsciously was following the prescription of 
Brown-Sequard. Brain-fatigue had made the continuation 
of the study which caused it impossible. The condition is 
plainly stated in the following lines : 

The thread of Thought at last is broken, 
And knowledge brings disgust unspoken. 
Let us the sensual deeps explore. 2 

The brain has refused to work, and blind instinct, in the 
guise of dreams, whispers that there is in the organism 
something that can restore the intellectual forces. This 
something, however, is what is called sin, and much 
courage is needed to plunge into it. Without this evil, 
life cannot last. Faust has to choose between love and 
death, and chooses love. 

The end of the romance of Goethe and Frederique was 
bad, and that of Faust and Marguerite was still worse. The 
poet painted it in the most sombre colours. Marguerite 
killed her child, poisoned her mother, became crazy, and 
was beheaded. Faust's cup of misery was filled to the 
brim ; he blamed his evil genius, he made desperate efforts 
to save the poor woman, and cried "O that I had never 
been born." 

To sum up : in the first Part, Faust is a young, learned 
man who expects too much from science and life, and whose 
1 Op. at., p. 71. 2 Op. cit., p. 51. 


genius requires extra-conjugal love as a stimulant; he is 
unbalanced and inevitably pessimistic. It is not surprising 
that his life goes badly, and that his conduct leaves him 
much to repent of. But although, at first, a vague general 
discontent nearly drives him to suicide, later on the terrible 
evil which he had wrought on a poor creature he loved pas- 
sionately did no more than plunge him into misery that 
was bitter but far from mortal. His mind had developed 
far in the direction of optimism. The crisis through which 
he passed, serious as it was, ended by his return to a life of 
great activity and enterprise. 


The second Part of Faust is in the main a description of 
senile love Amorous passion of the old man Humble atti- 
tude of the old Faust Platonic love for Helena The old 
Faust's conception of life His optimism The general idea 
of the play 

THE first Part of Faust was acclaimed by the world almost 
as soon as it appeared, but the second Part met a very 
cold reception. Everyone knows and reads the first Part; 
the second Part has few readers, and these chiefly poets and 
dramatists. No doubt it has more effect on the stage than 
when it is read, but this is due to subsidiary features in 
which it resembles a fine ballet. There is general agree- 
ment that the real meaning of the second Part is obscure, 
complex and difficult to interpret. Many literary critics 
have racked their brains in the effort to discover the 
author's central idea. When Eckermann, who per- 
suaded Goethe to revise and finish the second Part, 
asked what was the meaning of some of the scenes in 
it, Goethe evaded the question and played the sphinx. 
Thus, with regard to the famous " mothers " Goethe 
answered, with a mysterious air: "You have the manu- 
script ; study it, and see what you can make of it " (January 
10, 1830). G. H. Lewes, although one of Goethe's most 
resolute admirers, admitted the impossibility of grasping 


the sense of the second Part. The Wanderjahre and the 
second Part of Faust were arsenals of symbols, and it 
pleased the old poet to see acute critics labouring to inter- 
pret them whilst he was silent and refused to help them. 
Lewes thought that Goethe, so far from showing the 
smallest wish to clear up their difficulties, took a pleasure in 
giving them new problems to puzzle over. Lewes himself 
thought that the second Part was poor in idea and execu- 
tion, and admitted that he had failed after repeatedly trying 
to get a conception of it that would reveal its beauties. In 
writing about it, he contented himself with giving a sum- 
mary of it. Now this second Part, although its general lines 
had been laid down for long, was actually written during 
several years in the last period of the poet's life. The fact 
that it was composed out of the regular sequence of the 
Acts and Scenes gives us an important clue. The third Act 
and then the second Part of the fifth Act were put OR paper 
first. Next followed the first Act and part of the second; 
the classical Walpurgis night was written in 1830, the 
fourth Act in 1831, and last of all the beginning of the fifth 

As the second Part of Faust is a crowded motley, con- 
taining many subjects, obviously of minor importance, 
such as the volcanic theory of the earth and the disquisition 
on paper-money, the key-note may be found in the portions 
which were first composed. Now Act III. contains the 
story of Helena, and the second part of Act V. Faust's 
activity for the general welfare. 

Setting out from the conception that the works of Goethe 
reflect the acts and incidents of his own life, I shall try to' 
explain on that basis the meaning of the most obscure of 
his writings. 

I have already stated that love was the stimulus of 

u 2 


Goethe's activity in youth and age ; it is the scarlet thread 
running through his history. There was no difficulty in 
his using his love for Frederique as material for a play ; that 
a young man should love a young girl was natural enough. 
The story of an old man enamoured of a young beauty was 
quite another matter. It was said that one of the reasons 
that prevented his marriage with Ulrique de Lewetzow was 
the fear of ridicule (Lewes, op. cit., ii, p. 345), a fear that 
plays a large part in human affairs. It is easy to under- 
stand that the old poet was in a difficulty when he came to 
write of senile love. Faust's love for Helena was not that 
of a supposed old man who became young by doffing his 
beard and changing his cloak, but of a real old man whom 
no mystery nor magic was to make young again. And yet 
old Faust's love was a true passion, and Goethe has written 
no finer lines than those describing it. 

When the second Part begins, Faust has passed through 
the terrible crisis of the first Part. Wearied and restless, 
he seeks a new mode of life. 

Life's pulses now with fresher force awaken 
To greet the mild ethereal twilight o'er me; 
This night, thou, Earth ! hast also stood unshaken, 
And now thou breathest, new-refreshed before me, 
And now beginnest, all thy gladness granting, 
A vigorous resolution to restore me, 
To seek that higher life for which I'm panting. 1 

The invoked image of the most beautiful woman in the 
history of the world transforms Faust's desire of love into 
an overwhelming passion. 

Have I still eyes? Deep in my being springs 
The fount of Beauty, in a torrent pouring ! 
A heavenly gain my path of terror brings. 
The world was void, and shut to my exploring, 

1 Op. cit., p. 151. 


And, since my priesthood, how hath it been graced 1 

Enduring 'tis, desirable, firm-based. 

And let my breath of being blow to waste, 

If I for thee unlearn my sacred duty ! 

The form, that long erewhile my fancy captured, 

That from the magic mirror so enraptured, 

Was but a frothy phantom of such beauty ! 

'Tis Thou, to whom the stir of all my forces, 

The essence of my passion's courses, 

Love, fancy, worship, madness, here I render. 1 

In the throes of this passion, Faust is tortured by jealousy 
when he sees the lovely woman clinging to and kissing a 
young man. He desires her at all costs. 

Am I nothing here? To stead me, 
Is not this key still shining in my hand? 
Through realms of terror, wastes and waves it led me, 
Through solitudes, to where I firmly stand, 
Here foothold is ! Realities here centre ! 
The strife with spirits here the mind may venture, 
And on its grand, its double lordship enter! 
How far she was, and nearer, how divine 1 
I'll rescue her and make her doubly mine. 
Ye Mothers ! Mothers ! Crown this wild endeavour I 
Who knows her once must hold her, and for ever. 2 

The disappearance of the beautiful woman so moved 
Faust that he fainted and fell into a prolonged sleep. As 
soon as he recovered consciousness he asked : " Where is 
she? " and set out to seek for her. When he learned that 
Chiron had already carried off Helena on his back Faust 
cried out : 

Her didst thou bear? 
Chiron: This back she pressed. 
Faust: Was I not wild enough, before; 

And now such seat, to make me blest 1 

O, I scarcely dare l% . 

To trust my senses! tell me more! 

She is my only aspiration ! 

Whence didst thou bear her to what shore ? 2 

1 Op. at., p. 203. 2 Op. cit. p. 205. 3 Op. tit., p. 230. 


Thou saw'st her once; to-day I saw her beam, 
The dream of Beauty, beautiful as Dream ! 
My soul, my being, now is bound and chained; 
I cannot live, unless she be attained. 1 

Chiron found this attitude of passionate emotion so strange 
that he advised Faust to take care of his health. 

After many wanderings and difficulties Faust again met 
the woman he coveted and spoke to her as follows : 

What else remains, but that I give to thee 
Myself, and all I vainly fancied mine? 
Let me, before thy feet, in fealty true, 
Thee now acknowledge, Lady, whose approach 
Won thee at once possession and the throne ! 2 

This language, so very different from what the same man 
had formerly addressed to Marguerite, is much more like 
that of an old lover to a young beauty whom he admires. 
When Helena invited Faust to sit on the throne beside her, 
he replied : 

First, kneeling, let the dedication be 
Accepted, lofty Lady ! Let me kiss 
The gracious hand that lifts me to thy side. 
Confirm me as co-regent of thy realm, 
Whose borders are unknown, and win for thee 
Guard, slave and worshipper, and all in one ! 3 

The old man in the throes of a passion so great that he 
was wholly absorbed by it did not dare to address the 
beloved woman except in the most humble terms. 

Helena made no declaration of love, but was complacent 
to him, and when Faust suggested : " Now let our throne 
become a bower unblighted," Helena agreed to follow him 
to a secluded and green bower. There they remained alone 
for some time, cared for by an old servant. 

The result of this union was not a child like that to which 
Marguerite gave birth and afterwards killed. It was a 

1 Op- tit., p. 231. 2 Op. tit., p. 284. 3 Op. at., p. 287. 


strange and peculiar being ; a boy who immediately after 
his birth began to leap about and to alarm his parents by 
the activity of his movements. 

Although Goethe preserved an obstinate silence when he 
was asked to explain many of the scenes in the second Part, 
he had no hesitation in explaining the significance of this 
astonishing child. " The child was not a human being but 
an allegory, in which was personified poetry, which is not 
bound to any time, to any place, or to any person " (Ecker- 
mann, December 20, 1829). Struck by the tragic fate of 
Byron, Goethe made the son of Faust and Helena a symbol 
of the English poet. 

Literary critics, setting out from the categorical explana- 
tion of Goethe himself, have declared that the union of 
Faust and Helena was meant to denote the alliance of 
romanticism and classicism, a marriage from which was 
born modern poetry, personified in its highest representa- 
tive, Byron. This, however, cannot be the idea of Goethe, 
who himself was far from an enthusiast about classicism 
and romanticism. "What," he said, "is all this noise 
about the classic and the romantic ? The essential thing is 
that'a piece of work should be wholly good and serious; 
then it will also be classic " (Eckermann, October 17, 1828). 
It is much more probable that Goethe intended poetry to 
spring from the relations between the old Faust and his 
adorable companion, relations of a kind to be included in 
so-called platonic love. Such love inspires the creation of 
perfect work even in an old poet, when he is stimulated by 
a beautiful woman. 

When Faust and Helena emerged from the grotto with 
their son, Helena said : 

Helena: Love, in human wise to bless us, 
In a noble pair must be; 


But divinely to possess us, 

It must form a precious Three. 

Faust : All we seek has therefore found us ; 
I am thine and thou art mine ! 
So we stand as love hath bound us; 
Other fortune we resign. 1 

After the death of her son, Helena abandoned Faust, 
leaving him her garments : 

Helena : Also in me, alas I an old word proves its truth, 
That Bliss and Beauty ne'er enduringly unite. 
Torn is the link of Life, no less than that of Love; 
So, both lamenting, painfully I say : Farewell ! 
And cast myself again, once only, in thine arms. 1 

After this crisis the old Faust sought to console himself 
in the bosom of nature, just as after the terrible catastrophe 
with Marguerite the contemplation of nature had given him 
the strength to live. On this occasion he reached the sum- 
mit of a high mountain from which he watched the chang- 
ing vapours of a cloud which seemed to him to assume the 
form of female beauty. But Faust was old, and now saw 
only memories of love. He cried out : 

Yes ! mine eyes not err ! 
On sun-illumined pillows beauteously reclined, 
Colossal, truly, but a godlike woman-form, 
I see! The like of Juno, Leda, Helena, 
Majestically lovely, floats before my sight I 
Ah 1 now 'tis broken 1 Towering broad and formlessly, 
It rests along the east like distant icy hills, 
And shapes the grand significance of fleeting days. 
Yet still the-e clings a light and delicate band of mist 
Around my breast and brow, caressing, cheering me. 
Now light, delaying, it soars and higher soars, 
And folds together. Cheats me an ecstatic form, 
As early-youthful, long-foregone and highest bliss? 
The first glad treasures of my deepest heart break forth ; 
Aurora's love, so light of pinion, is its type, 
The swiftly-felt, the first, scarce-comprehended glance, 
Outshining every treasure, when retained and held. 

1 Op. cit., p 298. Op. tit., p. 305. 


Like Spiritual Beauty mounts the gracious Form, 
Dissolving not, but lifts itself through ether far, 
And from my inner being bears the best away. 1 

This state of mind resembles Goethe's condition after the 
rupture with Ulrique. 

Love and poetry alike were over for him. None the less 
his craving for the higher life was not yet weakened. The 
desire to live was still very strong in the old Faust. But 
now he no longer as in the days of his youth dreamed of 
an ideal which could not be attained. When Mephisto- 
pheles asked him ironically : 

Then might one guess whereunto thou hast striven? 

Boldly-sublime it was, I'm sure. 

Since nearer to the moon thy flight was driven, 

Would now thy mania that realm secure? 
Faust : Not so ! This sphere of earthly soil 

Still gives us room for lofty doing. 

Astounding plans e'en now are brewing : 

I feel new strength for bolder toil. 2 

Such optimistic language, extraordinarily different from 
Faust's lamentations in the first Part, becomes still more 
marked. When he was approaching his centenary he 
made the following profession of faith : 

I only through the world have flown : 
Each appetite I seized as by the hair; 
What not sufficed me, forth I let it fare, 
And what escaped me, I let go. 
I've only craved, accomplished my delight, 
Then wished a second time, and thus with might 
Stormed through my life : at first 'twas grand, completely, 
But now it moves most wisely and discreetly. 
The sphere of Earth is known enough to me ; 
The view beyond is barred immutably : 
A fool, who there his blinking eyes directeth, 
And o'er his clouds of peers a place expecteth 1 
Firm let him stand, and look around him well! 
This World means something to the Capable. 
Why needs he through Eternity to wend? 
He here acquires what he can apprehend. 3 
1 Op. at., p. 309. 2 Op. at., p. 313. 3 O p m dt ^ p< 35Ia 


When he had reached the maturity of his wisdom, 
Faust organised drainage works, the object of which was 
to increase the area of land that could be utilised : 

To many millions let me furnish soil, 

Though not secure, yet free to active toil; 

Green, fertile fields. 

A land like Paradise here, round about. 

Yes ! to this thought I hold with firm persistence ; 

The last result of wisdom stamps it true : 

He only earns his freedom and existence, 

Who daily conquers them anew. 

Thus here, by dangers girt, shall glide away 

Of childhood, manhood, age, the vigorous day : 

And such a throng I fain would see, 

Stand on free soil among a people free ! 

Then dared I hail the Moment fleeing : 

" Ah, still delay thou art so fair! " 

The traces cannot, of mine earthly being, 

In asons perish, they are there ! 

In proud fore-feeling of such lofty bliss, 

I now enjoy the highest Moment, this ! l 

These were the last words of the wise centenarian. It 
has been said that they contain the quintessence of 
Goethe's moral philosophy, and that they preach the sacri- 
fice of the individual for the benefit of society. Lewes, for 
instance, takes this view, holding that Faust was the ex- 
position of a man who had conquered the vanity of in- 
dividual aspirations and joys, and had come to the know- 
ledge of the great truth that man must live for man, and 
can find lasting happiness only in work for the benefit of 
humanity. For my own part, it seems to me that according 
to Goethe's Faust man must dedicate a large part of his 
life to the complete development of his own individuality, 
and that it is only in the second half of his life, when he 
has grown wise by experience and feels satisfied as an 
individual, that he should use his activity for the good of 

1 op. tit., PP . 354-355- 


mankind. It was no part either of the ideas of Goethe or 
of the nature of his work to preach the sacrifice of in- 

Goethe was thus absorbed in Faust by the problem 
of the conflict between certain actions and guiding prin- 
ciples. The misdeeds of the hero in the first Part of his 
life had to be redeemed. He said to Eckermann that " the 
key to the salvation of Faust was to be found in the Angels' 
Chorus " : 

The noble spirit now is free, 

And saved from evil scheming : 

Whoe'er aspires unweariedly 

Is not beyond redeeming. 1 

However, that of which he did not speak, and which 
none the less was most important in Faust and in Goethe 
himself, is the action of love as a stimulant to artistic 
creation, and it was probably to this that he referred at the 
end of his tragedy. The mystical chorus sent up prayers 
in a religious and erotic ecstasy, and their mysterious song 


The Indescribable, ' 

Here it is done; 

The Woman-Soul leadeth us 

Upward and on ! 2 

Although these verses have been interpreted as love 
which sacrifices or even love which leads to the grace of 
God (Bode, p. 149), it is much more probable that it is 
love for feminine beauty, a love which makes possible the 
execution of wonderful things. Such an interpretation 
agrees with the fact that the verses are spoken by a mystic 
choir which speaks of the indescribable (das Unbeschreib- 
liche) in which we must see the amorous passion of the 
old man. In such an interpretation the whole of Faust 
(and especially the second Part) is an eloquent pleading 
1 Op. at., p. 365. 2 Op. tit., p. 370- 


for the importance of love in the higher activity of man, 
in accordance with the law of human nature, which is a 
much better justification of Goethe's conduct than all the 
arguments of his interpreters and admirers. 

I do not agree with the common idea that the two Parts 
of Faust are two distinct works, but regard them as com- 
plementary. In the first Part we see the young pessi- 
mist, full of ardour and of desires, ready to make an end 
of his days and stopping at nothing to satisfy his thirst 
for love. In the second Part we have a mature old man 
still loving women, but in a different way, a man who is 
wise and optimistic, and who, having satiated the wants 
of his individual life, dedicates the rest of his days to man- 
kind, and who, having reached a century, dies extremely 
happy, in fact almost exhibiting the instinct of natural 




Difficulty of the problem of morality Vivisection and anti- 
vivisection Enquiry into the possibility of rational morality 
Utilitarian and intuitive theories of morality Insufficiency 
of these 

IN the course of this book I have from time to time ap- 
proached subjects closely related with the problem of 
morality. For instance, in considering the prolongation 
of human life, it was necessary to show that extension of 
longevity far beyond the reproductive period of man in 
no way is opposed to the principles of the highest morality, 
although there exist races who find the sacrifice of old 
people in harmony with their conception of morality. 

Experimental biology, which lies at the root of most of 
the doctrines exposed in this work, depends on vivisection 
of animals. There are, however, very many persons who 
regard it as immoral to operate on living animals when it 
is not for the direct benefit of these. The attempts which 
have been made in France and Germany to prevent or to 
limit vivisection in laboratories have not succeeded, but 
in England there is a severe law controlling operations on^ 
animals and submitting them to oppressive regulations to 
which many of the scientific men in the country are opposed. 

The question of experiments upon human beings is still 


more delicate. Just as formerly the examination of a 
human corpse could be made only in secret, so at the pre- 
sent time, if the slightest experiment is to be made upon a 
human being, it can be only by devious ways. People who 
are hardly shocked at all at the numberless accidents caused 
by automobiles and other means of transit, or in field 
sports, make the strongest protest against any proposal 
to try some new method of treatment upon a human 

A large number of people, amongst them even men of 
science, regard as immoral any attempt to prevent the 
spread of venereal diseases. Recently, in connection with 
the investigations into the action of mercurial ointment as 
a means of preventing syphilis, the members of the Faculty 
of Medicine in France made a public protest, declaring 
that it would be "immoral to let people think that they 
could indulge in sexual vice without danger," and that it 
was " wrong to give to the public a means of protection in 
debauch." 1 None the less, other men of science, equally 
serious, were convinced that they were performing an abso- 
lutely moral work in attempting to find a prophylactic 
against syphilis which would preserve many people, in- 
cluding children and other innocent persons who, if no 
preventive measures existed, would suffer from the terrible 

Such examples show the reader what confusion exists 
in the problem of morality. Although at every moment, 
in every act of human conduct, the precepts of morality 
must be reckoned with, even the most authoritative persons 
are far from agreeing as to what rules to follow. About a 
year ago in a Parisian journal 2 an enquiry into the subject 

1 V. Tribune medicale, 1906, p. 449. 
* La Revue, Nov. 1 5th and Dec. ist. 


of rational morality was directed to distinguished authors. 
The object was to discover if, at the present time, moral 
conduct could be based not on religious dogma, which 
binds only those who believe in it, but on rational prin- 
ciples. The answers were most contradictory. Some 
denied the possibility of rational morality, others admitted 
it, but in very different fashions. Whilst one philosopher, 
M. Boutroux, held that "morality must be founded on 
reason and could have no other foundation," a poet, M. 
Sully-Prudhomme, turned to feeling and conscience as the 
basis of morality. According to him, " in the teaching of 
morality, it is the heart and not the mind which is at 
once master and pupil." In the contradictions which I 
mentioned in the beginning of this chapter, these two 
views appear. When antivivisectionists are protesting 
against experiments on animals, they are inspired by sym- 
pathy for poor creatures which cannot defend themselves. 
Guided by conscience, they think immoral any suffering in- 
flicted upon a living being for the benefit of another being, 
whether human or animal. I know distinguished physio- 
logists who have determined to limit their experiments to 
animals with little sensibility, such as frogs. The great 
majority of scientific men, however, would have no scruple 
in opening bodies and subjecting their victims to severe 
suffering in the hope of clearing up some scientific problem 
which sooner or later would increase the happiness of 
human beings and animals. If vivisection had not been per- 
formed, or if it had been restricted, the great laws of infec- 
tious diseases would not have been discovered, nor would 
the discovery of many valuable remedies have been made. 
To justify investigation, men of science set out from the 
utilitarian theory of morality, which approves everything 
that is useful to the human race. The antivivisectionists, on 


the other hand, rely on the intuitive theory, according to 
which conduct is controlled by the spontaneous activity of 
our conscience. 

In the case which I have selected the problem is easy to 
solve. It is plain that vivisection is inevitable in the ex- 
perimental investigation of vital processes, as it is the only 
means by whch serious progress can be made. None the 
less, very many people cannot accept this necessity, 
because of the intensity of their love for animals. 

In the question of the prevention of syphilis, the moral 
problem is still more easy to settle. Whilst in the case of 
vivisection a real suffering may be inflicted upon animals, 
in preventive measures against syphilis, the evil is more 
or less intricate and very problematic. The certainty of 
safety from this disease might render extra-conjugal rela- 
tions more frequent, but if we compare the evil which 
might come from that with the immense benefit gained in 
preventing so many innocent persons from becoming dis- 
eased, it is easy to see to which side the scale dips. The 
indignation of those who protest against the discovery of 
preventive measures can never either arrest the zeal of the 
investigators or hinder the use of the measures. This 
example again shows that reasoning is necessary in the 
solution of most moral questions. 

However, the problems which arise in actual life are 
often very much more complicated than the two cases I 
have taken as an introduction. It is easy to prove the 
high utility of the work of vivisectors and of those who 
are seeking means of preventing syphilis, whilst their 
adversaries have nothing to invoke but their feelings. The 
situation is quite different in many questions which border 
on morality. The sexual life abounds in extremely diffi- 
cult problems, in which it is almost impossible to deter- 


mine what is right. Let me recall the vagaries in the life 
of Goethe, whose great genius was so often in conflict with 
the morality of his time. Was he wrong in giving up 
Frederique and Lili from the fear that a permanent bond 
would damage his poetic productivity ? Then there is the 
moral question of the marriage of men affected with 
syphilis, or other diseases which might influence the off- 
spring. The problems of the continence of young people 
before marriage, of prostitution and of means of prevent- 
ing conception are without doubt questions of great im- 
portance, the solution of which is extremely difficult from 
the point of view of morality. Differences of opinion are 
revealed in nearly everything relating to punishment. 
The question of the death penalty is much in dispute 
and requires numerous investigations of different kinds. 
Statistics have been collected to give information as to the 
utility or inutility of the death penalty. According to 
some results, capital punishment does not diminish the 
number of crimes, whilst according to others it has a real 
preventive effect. Punishments less violent than death, 
and particularly the punishments of children, are equally 
troublesome, and schoolmasters have difficulty in finding 
a solution. 

The utilitarian theory of morality often finds it impos- 
sible to prove the advantage of the conduct it prescribes, 
and this the more because in many cases we do not exactly 
know who is to profit by it. Is the utility of any par- 
ticular act to be considered so far as it affects relatives, 
members of the same religion, of the same country, or 
of the same race, or all humanity ? 

In face of these difficulties, many moral philosophers have 
given up the utilitarian theory and declared for an intui- 
tive theory. The basis of morality is to be found in a 



feeling innate in every man, a sort of social instinct urging 
him to do good to his neighbour, and which, by the voice 
of his own conscience, dictates how he ought to act much 
more precisely than could be done by any comprehension 
of the utility of his conduct. 

It is certainly true that man is an animal living in society 
because of his need for association with other human 
beings. But whilst in the animal world the members of 
societies are actuated by an instinct which is blind and 
generally very precise, in man we find nothing of the kind. 
The social instinct appears in him in endless variety. In 
some of us love of neighbours is extremely highly 
developed, so that some persons are only happy when 
sacrificing themselves for the public good. They give all 
that they have to the poor, and often die for some ideal 
which is necessarily altruistic. Such examples are rare. 
Many men, however, profess an affection for some of their 
kind, devote themselves to their relations, their friends, or 
their compatriots, and remain practically indifferent to all 
others. Other individuals, again, have an even narrower 
sphere of affection, and take advantage of their fellows, 
either in their own interest or in that of their own family. 
Still more rare are the really wicked persons who have no 
love for anyone but themselves and who take pleasure in 
doing harm to those about them. Notwithstanding this 
diversity in the development of the social instinct, all men 
have to live together. 

If it were possible to know the inner motives of men, 
these might be used as a basis for classifying conduct. 
Those acts might be described as moral which were in- 
spired by neighbourly love, and those as immoral the 
motive of which was egoism. But it is seldom that the 
real motives are discovered; they lie deep down in the 


individual mind, sometimes unknown even to the man him- 
self. We can nearly always harmonise our acts with the 
dictates of our consciences and find reasons for the harm 
we inflict upon others. It is only rare natures that possess 
a conscience so delicate as to be always tormented lest they 
are not doing good to their neighbours. 

In the course of life, men are disposed to attribute bad 
motives to their opponents. Such an attitude makes 
criticism easier and panders to the common wish to speak 
evil of one's neighbours. Notwithstanding the numerous 
precedents for such an attitude amongst politicians and 
journalists, it must be discarded from any serious study of 

The motives and the conscience are elusive elements of 
little use in any attempt to value human conduct. We 
have to fall back on the consequences of action. Now it 
is easy to show that the social instinct often leads to action 
which is not good. It frequently happens that men, acting 
with the highest and best intentions, do much harm. 
Schopenhauer long ago pointed out that morality based on 
sentiment is a mere caricature of real morality. Impelled 
by the altruistic wish to do good, men often lavish unre- 
flecting charity and do harm to others and to themselves. 
In Timon of Athens Shakespeare depicted 

A most incomparable man ; breathed, as it were, 
To an untirable and continuate goodness, 

and who gave away to the right and the left, creating 
around him a cloud of parasites. He finally ruined him- 
self and became a hopeless misanthrope. Shakespeare put, 
his verdict in the mouth of Flavius : 

Undone by goodness. Strange, unusual blood, 
When man's worst sin is, he does too much good. 

X 2 


Morality, founded purely on sentiment, has inspired the 
attacks on vivisectors which in all confidence spread evil 
amongst men. 

It is a surprising result of the great complexity of human 
affairs, that society is sometimes better served by wicked 
acts than by acts inspired by the most generous feelings. 
Thus extremely rigorous measures of repression are often 
more successful than the half-measures employed by 
humane and charitable administrators. 

The intuitive theory of morality has had no greater suc- 
cess than utilitarianism. Even if the sentiment of society 
were a true basis of moral conduct, it fails in actual practice. 
On the other hand, although utility is the object of all 
morality, it is in most cases so difficult to determine what is 
really useful, that utilitarianism breaks down as the founda- 
tion of morality. 

We must look elsewhere for principles which can guide 
us towards right conduct. 



Attempts to found morality on the laws of human nature 
Kant's theory of moral obligation Some criticisms of the 
Kantian theory Moral conduct must be guided by reason 

EVEN in antiquity, there were efforts to find a basis for 
morality other than the precepts of religion based on revela- 
tion, but the failure of such attempts has long been ad- 
mitted. In the first chapter of The Nature of Man, I 
described such efforts to find a basis for morality in human 
nature itself. The Epicureans and the Stoics, although 
their doctrines were opposed, each claimed to set out from 
human nature. The principle is too vague for practical 
use, as human nature can be interpreted in very different 

When several attempts to find a rational basis for morality 
had failed, Kant's theory appeared and was hailed by many 
as a real advance. None the less, it has not met with 
general approval and may be taken as a supreme instance 
of the failure to solve the great problem of morality by 
reason. I do not wish to deal with it at length, but a 
review of its main outlines is pertinent to my argument. 

According to Kant, morality cannot be founded on the 
feeling of sympathy, nor can it have as its object the happi- 
ness of men. Nature w-ould have been an unskilful work- 


man were her object the happiness of human beings, for 
many lower animals have much more happiness. An inner 
law is the force compelling us to morality, and without that 
we should have to seek our guide in happiness. 

Kant's doctrine is an intuitive theory of morality. It is 
Based neither on sympathy nor on any inherent charity, 
which would make us covet happiness for our fellows, but 
solely on the consciousness of duty. Kant thought that 
the action of a man who wished to do good to his fellows 
was devoid of merit. Conduct was moral only in so far 
as it was obedience to the inner sense of duty. Schiller's 
epigram has thrown into relief this part of the great philo- 
sopher's theory, "When I take pleasure in doing good to 
my neighbour, I am uneasy, as I fear that I have been 
lacking in virtue." 

In his criticism of Kant's system, Herbert Spencer drew 
a picture of a world inhabited by men who had no sym- 
pathy for their fellows and who did good to them against 
their natural instincts and only from a pure sense of duty. 
Spencer thought that such a world would be uninhabitable. 
Clearly, moral conduct, on the Kantian basis, could be 
followed only by exceptional persons, for most men follow 
their inclinations rather than any sense of duty. People 
of lower culture would accept kindnesses from others with- 
out caring whether the motive were kindness or a sense of 
duty, but highly civilised people would not endure service 
from those whom they knew to be acting against their 
instincts in obedience to a sense of duty. And so men 
would be driven to hide the real motives of their conduct, 
lest they should offend the sensibility of those towards 
whom their moral conduct was directed. Such cases, where 
the real motive is concealed, show how impossible it is to 
judge of conduct from the motives which may be supposed 


to have inspired it. As it is generally impossible to know 
whether some altruistic conduct has been inspired by kind- 
ness or has been performed as a duty, it is better to give 
up any attempt to appraise the springs of moral conduct. 

Kant himself realised the need of some other standard 
for appraising human conduct. With such a purpose he 
arrived at his well-known maxim : " Let your conduct be 
such that your motive might serve as a standard of uni- 
versal application." To explain the maxim he gave a 
number of examples. A man who is without money and 
cannot pay a debt is in doubt as to whether he should 
promise to repay his creditor. According to Kant, he 
ought to ask himself what would be the result if such a 
promise were to be made under similar circumstances by 
everyone. It is plain that if such false promises became 
universal, they would cease to be believed and so would 
be impracticable in actual life. Kant's formula, therefore, 
would supply a rational basis for the discrimination of 
immoral conduct. In the case of theft it would operate as 
follows : if it became the custom for everyone to take what- 
ever he wanted, private property and theft would simul- 
taneously cease to exist. So also suicide is immoral, since 
if it became general the human race would cease to exist. 

Kant, however, was looking at only one side of the 
problem. Moral conduct is frequently limited to an indi- 
vidual, and cannot be generalised for all humanity. Thus, 
for instance, if one about to sacrifice his life for the good 
of his fellows were to estimate his action according to 
Kant's formula, he would reach a conclusion similar to that 
in the case of suicide; if everyone were to sacrifice his life 
for others, no one would remain alive, and so, according to 
Kant, the sacrifice of one's life for the good of others would 
be an immoral act. 


It is plain that in his search for a rational basis of moral- 
ity, Kant found only a hollow form, void of any substantial 
body of morality. It is not enough that a moral man 
should take his consciousness of duty as a guide. He must 
know what would be the result of his acts. If it is immoral 
to make a false promise, it is because people would lose 
confidence in such promises, and confidence is necessary 
to our well-being. When the formula of Kant condemns 
theft, it is because, if theft became general, there could be 
no private property, and property is regarded as necessary 
to the well-being of men. Suicide is immoral, according to 
Kant, because it would lead to the disappearance of the 
human race, and human life is of course a good. 

Kant tried to found his theory of morality on a rational 
basis which excluded the idea of the general good, but it 
was impossible for him to avoid it. His " practical reason," 
when it raised the consciousness of duty to a principle, 
should have pointed the goal towards which moral acts 
were to be directed. In this matter, I find that Kant's 
ideas are very vague, although extremely interesting. 

The innate feeling of duty implies the will to pursue 
moral conduct. This will is independent of the circum- 
ambient conditions. Kant in his nebulous language ex- 
plains this consideration as follows : " Our reason informs 
us of a law to which all our maxims are subject, as if our 
will had created its own natural order of things. This law, 
then, is in the sphere of a nature which we do not know 
empirically but which the freedom of the will makes possible, 
a nature which is supra-sensible, but which from the prac- 
tical point of view we make objective, because it is created 
by our will in virtue of our existence as rational beings. 
The difference between the laws of a nature to which the 
will is subject and a nature subject to the will subsists in 


this, that in the first the objects must be the causes which 
determine -the will, whilst in the second, the will itself 
causes the objects so that the causality of the will resides 
exclusively in pure reason, pure reason being thus practical 
reason " (Critique of Practical Reason). 

So far as I can follow the argument of Kant, it seems to 
me to imply that rational morality cannot be bound by 
human nature as it exists. I may perhaps interpret Kant's 
thought as if he had the intuition that the moral will was 
capable of modifying nature by subjecting it to its own 

On the other hand, several critics of Kant have attempted 
to improve his theory of morality by reconciling it with 
human nature as it actually exists. Vacherot, 1 for instance, 
has taken such an attitude in the most definite fashion. 
He insists that Kant "did not appreciate the capital im- 
portance of the object of the moral law. The problem 
which under the designation summum bonum absorbed 
the schools of antiquity plays a minor part in the Kantian 
theory. Kant should have recognised that human destiny 
is not limited to duty but must include happiness " (p. 316). 

But what is this " happiness " which is to be the standard 
of human actions ? To answer this Vacherot places him- 
self in the position of those ancient philosophers whom I 
discussed in The Nature of Man. He makes his point 
absolutely clear. "What is the 'good' for any being? 
The attaining of its purpose. What is the purpose of a 
being ? The simple development of its nature. Apply 
this to man and morality. When human nature is known 
by observation and analysis, the deduction can be made as 
to what is the purpose, and the good, and therefore the law 
,of man. For the conception of the good necessarily in- 

1 Essais de Philosophie critique, Paris, 1864. 


volves the idea of duty and of law to be imposed on the 
will. We have to fall back, then, on knowledge of man, but 
it must be complete knowledge, a recognition of the facul- 
ties, feelings, and inclinations that are peculiar to him and 
that distinguish him from animals" (p. 319). Here is a 
summary of this doctrine: "Develop all our natural 
powers, subordinating those which are subsidiary to those 
which form the peculiar quality of human beings ; this is 
the true economy of the little world we call human life; 
this is its purpose and this its law. The formula states in 
the most scientific and least doubtful form a very old truth, 
the foundation of all morality and the test of all its applica- 
tions. If we seek to know what are justice, duty and 
virtue, we must look in the world itself, and not above or 
below it" (Op. 301). 

Professor Paulsen, a more recent critic of Kant, comes 
to a similar conclusion. 1 He thinks that Kant should have 
modified his formula in some such way as follows : " The 
laws of morality are rules which might serve for a natural 
legislation for human life; in other words, rules that, when 
they guided conduct according to natural law, would result 
in the preservation and supreme development of human 

From whatever side we examine the problem of morality, 
we come to submit conduct to the laws of human nature. 
Sutherland, a modern author who discusses morality by 
the scientific method, defines morality as " conduct guided 
by rational sympathy." Such sympathy would not subor- 
dinate the chief good of others to an advantage less impor- 
tant but more immediate. Thus a mother may sympathise 
with her child when it has to take some unpleasant 

1 System der Ethik^ 7th and 8th editions, vol. i, p. 199. Berlin 



medicine; but if her sympathy be rational she will not let 
it interfere with the health of the child. 

In the foregoing case, sympathy has to be controlled by 
medical knowledge. In moral conduct generally, reason 
must be the determining factor, whatever be the inspiring 
motive of the conduct, whether it come from sympathy or 
from the sense of duty. And thus morality in the last resort 
must be based on scientific knowledge. 



Individual morality History of two brothers brought up in 
same circumstances, but whose conduct was quite different 
Late development of the sense of life Evolution of sym- 
pathy The sphere of egoism in moral conduct Christian 
morality Morality of Herbert Spencer Danger of exalted 

ALTHOUGH moral conduct refers specially to the relations 
between men, there exists a morality of the individual. 
As this latter is simpler, I shall consider it first in my 
investigation of rational morality. 

When a man, seeking his individual happiness, gives 
way to his inclinations without restraint, he often comes to 
behave in a way that is generally regarded as immoral. 
Following his inclination, he may become idle and drunken. 
Idleness may depend on some irregularity of the brain, and 
may thus be as natural as is the wish to take drink in the 
case of a man to whom alcohol brings a feeling of well- 
being and gaiety. Why is it that idleness and alcoholism 
are immoral ? Is it because they prevent the living of life 
in its completest and widest sense, according to the theory 
of Herbert Spencer ? But it is precisely in this way that 
the adherents of the theory justify all kinds of excess with- 
out which fullness and width of life seem to them impos- 


Whilst vices such as idleness and drunkenness arise 
directly from qualities of the human constitution, they 
must be regarded as immoral because they prevent the 
completion of the ideal cycle of human life. I knew two 
brothers, almost the same age, subject to the same influ- 
ences, and brought up in the same environment. None 
the less, their tastes and conduct were very different. The 
older brother, although very intelligent, during his college 
career devoted himself eagerly to bodily exercises and 
indulged in every way his inclination for pleasure. " As 
the chief end of life is happiness," he said, "one must try 
to get as much of it as possible," and so he got into the 
habit of visiting places where there was most amusement. 
Cards, good living, and women furnished for him the means 
of pleasure. As his ability was unusual, he passed his 
examinations almost without having worked. The example 
of his younger brother, always a devoted student, did not 
attract him. "It is all very well for you," he said, "as 
you find your happiness in work ; as for me, I detest books, 
and I am happy only when I am giving myself up to 
pleasure. Everyone must take his own road to the goal 
of life." As a result, the health of the older brother w r as 
seriously affected by his mode of life. He acquired some 
disease of the circulatory system, had to face the end, 
and died at the age of fifty-six. The last years of his life 
were very unhappy, as the instinct of life developed in him 
extremely strongly. He was a victim of his own ignorance 
because when he was young he did not know that the sense 
of life would develop later on, and would become much 
stronger than in his youth. His brother was equally un- 
aware of this fact, but, absorbed in scientific study, he kept 
himself apart from the indulgences of youth and lived a 
sober life. In this way he found that his strength and 


activity were fully preserved at a time of life when his 
older brother was already a physical wreck. 

I have quoted this example, not to repeat the banal idea 
that a sober life is followed by a healthier old age than an 
intemperate life, but because I wish to insist on the import- 
ance of the development of the instinct of life in the course 
of each individual life. I see that this idea is very little 
known. I was present at the last moments of my older 
brother (he was called Ivan Ilyitch, and he was the subject 
of the famous story of Tolstoi : The Death of Ivan Ilyitch). 
Knowing that he was going to die from pyemia, at the 
age of forty-five, my brother preserved his great intelli- 
gence in all its clearness. As I sat by his bedside he 
told me his reflections in the most objective fashion 
possible. The idea of his death was for long very terrible 
to him, but " as we all die " he came to " resign himself, 
saying that after all there was only a quantitative difference 
between death at the age of forty-five and later on." This 
reflection, which relieved the moral sufferings of my 
brother, is none the less untrue. The sense of life is very 
different at different ages, and a man who lives beyond the 
age of forty-five experiences many sensations which he did 
not know before. There is a great evolution of the mind 
during the advance of age. 

Even if we do not accept the existence of an instinct of 
natural death as the crown of normal life, we cannot deny 
that youth is only a preparatory stage and that the mind 
does not acquire its final development until later on. This 
conception should be the fundamental principle of the 
science of life and the guide for education and practical 

Individual morality consists of conduct permitting the 
accomplishment of the normal cycle of life and ending in 


a feeling of satisfaction as complete as possible and which 
can be reached only in advanced age. And so, when we 
see a man wasting his health and strength and youth, and 
thus making himself incapable of feeling the most com- 
plete pleasure in life, we call him immoral. 

A man entirely isolated does not exist in nature. We 
are born weak and incapable of satisfying our needs and 
at once come into relations with the human being who 
feeds us and protects us. The child, although egoistic, 
becomes attached to his protector, and in this way the feel- 
ing of sympathy is born. Guided by this feeling as well 
as by the sense of his own interest, the child soon begins 
to employ his will in restraining some of his instincts, which, 
none the less, are quite natural. Thus, the fear of being 
deprived of food makes him obedient to his protectors. 
The child cannot complete his normal cycle without pursu- 
ing a certain moral conduct. 

When he becomes adult, man experiences the instinctive 
need of relations with someone of the other sex. This need 
lays certain duties on him, and although the love of a 
young man is less egoistical than that of the child, it is 
far from presenting the characters of self-abnegation and 

A young woman, after having passed through the usual 
cycle of life with her mother and with a man, becomes 
herself a mother. Maternal instinct furnishes her with 
certain rules of conduct, but this natural instinct is not 
enough to fulfil its object, that is to say, to rear the child 
until an age when it can live independently. Directed by 
a feeling of sympathy for her child, the young mother 
learns from women with more experience to ward off 
dangers from her child. In the first years, moral conduct 
on the part of the mother consists almost entirely in bring- 


ing up the child in a healthy way. For this purpose she 
must acquire much knowledge. If she remains ignorant, 
her conduct must be regarded as immoral. 

So far as concerns the bringing up of a child, the moral 
problem is quite simple, because we are all agreed that the 
object is to rear the child to maturity in the healthiest pos- 
sible condition. When the child exhibits any habits 
harmful to this object, although due to natural instincts, 
the mother applies her knowledge to restrain them without 
paying attention to the theory that happiness consists in the 
fulfilment of everything that is natural. When a child has 
passed through the perilous first period of its life, the 
mother has to ask what general object she is to follow in 
its education. She wishes her child to be as happy as 
possible. Here the conception of orthobiosis will serve 
her, and it will teach her that the greatest happiness con- 
sists in the normal evolution of the sense of life, leading 
to serene old age, and finally reaching the fulness of satiety 
of life. Man, who has passed his apprenticeship to life 
from his birth, with his protectors, and, later on, with 
persons of the other sex, inevitably acquires certain 
elements necessary for social life. Persuaded that in order 
to succeed in his individual life he must have help from 
his fellows, he learns to subdue his anti-social tendencies, 
at first in his own interests. Let me take an example of 
this. When a man has reached a certain stage of civilisa- 
tion, it generally becomes impossible to him to supply his 
bodily wants without the help of persons less cultured than 
himself. He takes into his house one or more servants, 
with whom he enters into definite relations. He wishes for 
himself and those about him a normal life, such as I have 
described in The Nature of Man. To attain this it is in- 
dispensable in his own interest and in that of his family, 


that his domestic servants should be well treated. The 
health of the family very often depends on the conduct of 
the servants, who will follow conscientiously the hygienic 
rules only if they themselves are living in good conditions. 
The custom according to which the masters live in luxu- 
riously furnished rooms, while their servants have mean 
quarters in the attics, is immoral from the point of view of 
the well-being of the masters themselves. The crowded 
servants' quarters are a nest of all sorts of infection, which 
may spread in the families of the masters. Very often 
people who think that they are following the rules of exact 
hygiene contract diseases without knowing that the infec- 
tion has come from their servants. 

Anger gives us another example. It is certainly harmful 
to the health, and so should be controlled in the interest 
of the bad-tempered person himself. Fits of rage are fre- 
quently followed by ruptures of blood-vessels, and by 
diabetes, and even cataracts have developed after some 
violent passion. 

Luxurious habits are also well known to be harmful to 
the health. Heavy meals, evenings passed in the theatre 
and in society may seriously affect activity of the organs. 
Moreover, the luxury of some people is often the cause of 
misery to others. The knowledge that luxurious habits 
shorten life and prevent man from reaching the greatest 
happiness may warn people against luxury better than 
the appeal to the feeling of sympathy. 

As it is a fact that most men guide their lives generally 
from egoistic motives, any theory of morality which is to 
be put into practice must reckon seriously with this factor. 
All other systems have recognised it. In the Sermon on 
the Mount, which is a summary of Christian morality, each 
moral act is recognised on the ground that it will bring 



some reward or obviate some punishment. " Rejoice," 
said Jesus, "and be exceeding glad; for great is your 
reward in heaven" (Matt, v., 12). "Take heed that ye 
do not your alms before men, to be seen of them ; otherwise 
ye have no reward of your Father which is in heaven" 
(Matt, vi., i). "That thine alms may be in secret; and 
thy Father which seeth in secret himself shall reward thee 
openly" (Matt, vi., 4). "Judge not, that ye be not 
judged" (Matt, vii., i). "But if ye forgive not men 
their trespasses, neither will your Father forgive your tres- 
passes " (Matt, vi., 15). Jesus had no high opinion of 
the influence of altruism on human conduct. 

Herbert Spencer in his treatise on morality (The Data 
of Ethics) also insists that laws of conduct, to be of 
general application, must not require men to make too great 
sacrifices, as otherwise the best teaching would remain a 
dead letter. He imagines, however, that in the future the 
human race will be so much improved that moral conduct 
will become instinctive, needing no compulsion. The Eng- 
lish philosopher presents a view of the future of the human 
race totally at variance with the Kantian conception. 
Instead of human beings becoming filled with a sense of 
duty opposed to their natural instincts, the world will be 
peopled with men acting morally from inclination, so 
making the world delightful. 

The ideal is so far removed from existing conditions that 
the possibility of its attainment is hardly worth consider- 
ing. It is probable that a world whose inhabitants had 
the feeling of sympathy very highly developed would not 
be so delightful. For sympathy is generally a reaction 
against evil. When evil disappears, sympathy would be 
not merely useless, but annoying and harmful. 

George Eliot in Middlemarch describes a young woman 


enthusiastically anxious to do good to her fellows. When 
she came to live in a village, she made great plans to 
succour its poor. Her disillusion and annoyance were 
great when she found that the villagers were quite com- 
fortably off, and had no need of her charity. 

John Stuart Mill in his Autobiography relates that when 
he was young he dreamed of reforming society and making 
everyone happy. But when he asked himself if the accom- 
plishment of his beautiful ideas would make him happy, 
he was compelled to answer "No! " and this discovery 
plunged the young philosopher into a lamentable condi- 
tion. He described himself as quite overcome, all that 
supported him in life crumbling away. His happiness 
could lie only in the constant pursuit of his object, and the 
charm seemed broken, because if attainment were not to 
please him, how could the means be of any interest to 
him ? It -seemed to him that nothing was left to which 
he could dedicate his life. 

As it is highly probable that with the advance of civilisa-. 
tion the greatest evils of humanity will become lessened, 
and may even disappear, the sacrifices to be made will also 
become less. Now that there is a serum which protects 
against plague, there is no room for the heroism of the 
doctors who used to incur the greatest danger in fighting 
epidemics. Until lately doctors used to risk their life in 
treating the throats of diphtheric patients. A young doctor 
who was a friend of mine, of high ability and promise, died 
from diphtheria contracted under these conditions. He 
met his death, in isolation from his friends in case of infect- 
ing them, with the utmost heroism. Now that the anti- 
diphtheric serum has been discovered, such heroism would 
be unnecessary. The advance of science has removed the 
occasion of such sacrifices. 

Y 2 


It is now very long since there has been opportunity for 
the heroism which steeled the hand of Abraham to sacri- 
fice his only son to his religion. Human sacrifice, based on 
the highest morality, has become more and more rare, and 
will finally disappear. Rational morality, although it may 
admire such conduct, has no use for it. So also, it may 
foresee a time when men will be so highly developed that 
instead of being delighted to take advantage of the sym- 
pathy of their fellows, they will refuse it absolutely. 
Neither the Kantian idea of virtue, doing good as a pure 
duty, nor that of Herbert Spencer, according to which 
men have an instinctive need to help their fellows, will be 
realised in the future. The ideal will rather be that of 
men who will be self-sufficient and who will no longer 
permit others to do them good. 



Human nature must be modified according to an ideal 
Comparison with the modification of the constitution of 
plants and of animals Schlanstedt rye Burbank's 
plants The ideal of orthobiosis The immorality of ignor- 
ance The place of hygiene in the social life The place of 
altruism in moral conduct The freedom of the theory of 
orthobiosis from metaphysics 

As I have shown in The Nature of Man, the human con- 
stitution as it exists to-day, being the result of a long 
evolution and containing a large animal element, cannot 
furnish the basis of rational morality. The conception 
which has come down from antiquity to modern times, of 
a harmonious activity of all the organs, is no longer appro- 
priate to mankind. Organs which are in course of atrophy 
must not be reawakened, and many natural characters 
which perhaps were useful in the case of animals must be 
made to disappear in men. 

Human nature, which, like the constitutions of other 
organisms, is subject to evolution, must be modified accord- 
ing to a definite ideal. Just as a gardener or stock raiser 
is not content with the existing nature of the plants and 
animals with which he is occupied, but modifies them to 
suit his purposes, so also the scientific philosopher must 
not think of existing human nature as immutable, but must 
try to modify it for the advantage of mankind. 


As bread is the chief article in human food, attempts 
to improve cereals have been made for a very long time. 
Rimpau made one of the greatest steps in this direction 
when he introduced into cultivation a variety of rye known 
as Schlanstedt rye, now fairly abundant in France and 
Germany. Rimpau set himself the task of producing a 
variety with the longest ears and containing many and 
heavy grains. Having conceived his ideal, he began to 
seek out what was nearest to it in a very large number of 
examples of rye. After patient and continued labour, 
using careful selection and cross-fertilisation, Rimpau 
succeeded in making the new variety, and so did a great 
service to mankind. 

Burbank, 1 an American horticulturist, has recently 
gained a wide reputation because of his improvements of 
useful plants. He has produced a new kind of potato 
which has raised the value of potato crops in the United 
States by about .3,500,000 per annum. Burbank cultivated 
great numbers of fruit trees, flowers, and all kinds of 
plants, with the object of increasing their utility. One of 
his objects was to produce varieties which could resist 
dry conditions, which reproduced rapidly and so forth. 
He has modified the nature of plants to such an extent that 
he has cactus plants and brambles without thorns. The 
succulent leaves of the former provide an excellent food for 
cattle, whilst the absence of thorns in the latter makes 
their pleasant fruit more suitable for gardens. Burbank 
has enormously improved the production of stoneless 
plums, and has very much reduced the price of many bulbs 
and lilies by increasing their productivity. 

To obtain such results much knowledge and a long 
period of time were necessary. To modify the nature of 
1 De Vries, in Biologisches Centralblatt, 1906, Sept. ist, p. 609. 


plants it was necessary to understand them well. To frame 
the new ideal of the plant it was necessary not only to have 
an exact conception of what was wanted, but to find out if 
the qualities of the plants in question furnished any hope 
of realising it. 

The methods which have been successful in the case of 
plants and animals must be much modified for application 
to the human race. In the case of human beings the selec- 
tion and cross-breeding which were imposed upon rye and 
plum trees are not possible, but, at the same time, the 
ideal of human nature, towards which mankind ought to 
press, may be formed. In our opinion this ideal is ortho- 
biosis, that is to say, the development of the human life 
so that it passes through a long period of old age in active 
and vigorous health, leading to the final period in which 
there shall be present a sense of satiety of life, and a 
wish for death. I do not think that the ideal should be 
that of Herbert Spencer, a simple prolongation of human 
life. When the instinct of death comes at a not very late 
period of life, there would be no inconvenience in shorten- 
ing the life, if death did not come soon after the appear- 
ance of the instinct. Probably this would be the only case 
where suicide was justified in the conception of orthobiosis. 

The foregoing is the case of an action in conformity 
with the ideal, but quite contrary to human nature as it is 
at present. A similar contradiction appears in reproduc- 
tion. Man came from animals amongst which unlimited 
reproduction was an important factor in the preser- 
vation of the species, as it allowed the species to survive 
under all sorts of bad conditions, such as diseases, com- 
bats, attacks of enemies, and changes of climate. Although 
man, according to the laws of human nature, is capable 
of reproducing extremely rapidly, the ideal of his happiness 


makes a restriction of this power necessary. Thus ortho- 
biosis, based upon knowledge of human nature, would set 
limits to a function which is perhaps the most natural of 
all. The restriction which is already partially adopted 
will come more and more into operation as the struggle 
against diseases, the prolongation of human life, and the 
suppression of war make progress. It will be one of the 
chief means of diminishing the most brutal forms of the 
struggle for existence, and of increasing moral conduct 
amongst mankind. 

Just as Rimpau began to study the nature of plants 
before trying to realise his ideal, so also varied and pro- 
found knowledge is the first requisite for the ideal of moral 
conduct. It is necessary not only to know the structure 
and function of the human organism, but to have exact 
ideas on human life as it is in society. Scientific know- 
ledge is so indispensable for moral conduct that ignorance 
must be placed among the most immoral acts. A mother 
who rears her child in defiance of good hygiene, from want 
of knowledge, is acting immorally towards her offspring, 
notwithstanding her feeling of sympathy. And this also 
is true of a Government which remains in ignorance of the 
laws which regulate human life and human society. 

It must be well understood that I am not here thinking of 
written knowledge, set down in treatises and volumes. 
Rimpau and Burbank went outside manuals of botany to 
obtain their knowledge. Besides books, wide ideas on the 
practice of life are required to direct aright the conduct of 
men. A doctor who has just finished his studies at the 
hospital, notwithstanding all his knowledge, is not yet suffi- 
ciently trained to be a good practitioner. He must acquire 
the habit of treating patients, and for this years are re- 
quired. So also is it with regard to the practical applica- 


tions of the principles of morality. The regulation of 
conduct requires profound knowledge both theoretical and 
practical, and men selected to frame or to apply laws of 
morality must have this double qualification. If the human 
race come to adopt the principles of orthobiosis, a consider- 
able change in the qualities of men of different ages will 
follow. Old age will be postponed so much that men of 
from sixty to seventy years of age will retain their vigour, 
and will not require to ask assistance in the fashion now 
necessary. On the other hand, young men of twenty-one 
years of age will no longer be thought mature or ready to 
fulfil functions so difficult as taking a share in public affairs. 
The view which I set forth in The Nature of Man regard- 
ing the danger which comes from the present interference of 
young men in political affairs has since then been confirmed 
in the most striking fashion. 

It is easily intelligible that in the new conditions such 
modern idols as universal suffrage, public opinion, and the 
referendum, in which the ignorant masses are called on to 
decide questions which demand varied and profound know- 
ledge, will last no longer than the old idols. The progress 
of human knowledge will bring about the replacement of 
such institutions by others, in which applied morality will 
be controlled by the really competent persons. I permit 
myself to suppose that in these times, scientific training 
will be much more general than it is just now, and that it 
will occupy the place which it deserves in education and in 

It is equally clear that if a mother is to act morally with 
regard to her child, she must teach herself properly. In 
place of mythology and literature, she must learn hygiene 
and all that relates to the rational rearing of children. So, 
also, in the education of men, the study of the exact 


sciences must occupy by far the most important place. 
Then only will moral conduct and scientific knowledge 
begin to unite. An ignorant mother will bring up a child 
very badly notwithstanding all her good will and her affec- 
tion. A doctor, however imbued with strong sympathy for 
his patients, could do them much harm if he had not the 
appropriate knowledge. Are not politicians open to the 
reproach from the point of view of morality that very often 
through ignorance they do the very worst evil in public 
administration ? With the progress of knowledge, moral 
conduct and useful conduct will become more and more 
closely identified. 

I have been reproached because in my system the health 
of the body occupies too large a place. It cannot be other- 
wise, because health certainly plays the chief part in exist- 
ence. Notwithstanding his pessimism, Schopenhauer was 
convinced that health was the greatest treasure, a treasure 
before which everything else yielded. In many religions 
care of the health is laid down amongst the chief duties. 
Although many scientific men do not hold the opinion 
that circumcision was ordained for hygienic reasons, it 
is certain that hygiene was extremely important in the 
Jewish religion. It is only in Christianity, which despises 
the human body, that hygiene is excluded from the re- 
ligious code, as in the words of Jesus : 

"Take no thought for your life, what ye shall eat, or 
what ye shall drink ; nor yet for your body, what ye shall 
put on. Is not the life more than meat, and the body 
than raiment?" (Matt, vi., 25). As for long ages 
hygiene was very imperfectly known, it is not surprising 
that it played a small part in human affairs. Probably 
the objection to the importance that I assign to it in ortho- 
biosis is a relic from the old order of things. Now, how- 


ever, the situation is different. Bacteriology has placed 
hygiene on a scientific foundation, so that the latter is now 
one of the exact sciences. It has now become necessary 
to give it the chief place in applied morality as it is the 
branch of knowledge that teaches how men ought to live. 

It has been objected that I have left no place for altruism 
in my system. 1 Certainly I have tried to find an egoistic 
basis for moral conduct, as I have shown above. I think, 
however, that the wish to live according to the ideal of 
orthobiosis and to make others live a normal life would be 
a powerful agency in improving social life, in preventing 
mutual damage, and promoting mutual help. Such a 
motive, within the reach of persons whose altruistic feel- 
ings are not specially strong, must largely extend moral 
conduct amongst human beings, and even although in 
future such manifestations of high morality as the sacrifice 
of life and health will become wholly or nearly wholly 
useless, I think that for the present there is still room for 
altruism. The practical application of scientific knowledge 
already gained admits much self-denial and good feeling. 
Struggle against prejudices of all kinds and the develop- 
ment and diffusion of sound ideas require a conduct very 
highly altruistic. 

The fears of my opponents are still less justified when 
we reflect that the feelings of sympathy and of cohesion 
must play a large part in the business of helping the 
evolution of man towards the goal of normal life. 

Although our actual knowledge already provides a basis 
of rational morality, it may be admitted that in the 
future, if science continues its forward march, the rules of 
moral conduct will become still more improved. There will 

1 Dr. Grasset, "La fin de la vie" in the Revue de philosephie^ Aug. 
ist, 1903. 


be no ground for reproaching me for a blind faith in the 
all-powerf illness of science. Much more trust can be given 
to one who has faithfully carried out his promises, than to 
one who has promised much and fulfilled nothing. Science 
has already justified the hopes which have been placed in it. 
It has saved people from the most terrible diseases, and 
has made life much easier. On the other hand, religions, 
which demand an uncritical faith as the means of curing the 
ills which afflict humanity, have not fulfilled their promises. 

The reproach that I preach blind faith in the progress of 
science, destined to replace religious faith, is unjust, because 
my faith depends on a confidence that science has already 
deserved. Equally unjust is the reproach that I have built 
my system on a partly metaphysical principle. Accord- 
ing to M. Parodi, 1 the hypothesis of physiological old age 
and of natural death seem to " involve the idea of a natural 
duration of human life, which, however, from accidental 
reasons man does not complete at present. M. Metchnikoff 
repeatedly uses the expression ' normal cycle.' Now do 
we not see here the surreptitious repetition of the old teleo- 
logical conception of nature, although at first he so ener- 
getically disavowed it ? It is the belief that the species is 
a necessary reality, corresponding to a definite type of its 
own, in fact a special design of nature; that nature, to 
guide herself, had an ideal which circumstances could 
mistake or degrade, but which had to be restored to its 
perfect form ? Otherwise, why does he insist that there 
must be a condition of perfect and stable equilibrium 
between individual and environment ? that there is a normal 
cycle and that it must be possible to harmonise the dis- 

I can show easily that all these objections rest upon a 
1 "Morale et biologic," Revue philosophique, 1904, vol. Iviii, p. 125. 


simple misunderstanding. I have never conceived of the 
existence of any ideal of nature or of the inevitable neces- 
sity of transforming disharmonies to harmonies. I have 
no knowledge of the " designs "and " motives " of nature ; 
I have never taken my stand on metaphysical ground. I 
have not the remotest idea if nature has any ideal and if 
the appearance of man on the earth were a part of such an 
ideal. What I have spoken of is the ideal of man corre- 
sponding to the need to ward off the great evils of old age 
as it is now, and of death as we see it around us. I have 
said, moreover, that human nature, that collection of com- 
plex features of multiple origin, contains certain elements 
which may be used to modify it according to our human 
ideal. I have done nothing but what the horticulturist 
does when he finds in the nature of plants elements which 
suggest to him to try and make new and improved races. 
Just as the constitution of some plum trees contains elements 
which make it possible to produce plums without stones 
which are pleasanter to eat, so also in our own nature there 
exist characters which make it possible to transform our 
disharmonious nature into a harmonious one, in accord- 
ance with our ideal, and able to bring us happiness. I 
have not the smallest idea what ideal nature may have on 
the subject of plums, but I know very well that man has 
such designs and such an ideal as form a point of de- 
parture for the transformation of the nature of plums. 
Substitute man for the plum tree and you are at my point 
of view. When I have spoken of the normal cycle of life 
or of physiological old age, I have used the words normal 
and physiological only in relation to our ideal of the 
human constitution. I might just as well have said that a 
cactus without thorns is the normal cactus in the conditions 
where it was desired to obtain a succulent plant useful as 


food for cattle. The words "normal" and "physio- 
logical " seemed to me more convenient than such a phrase 
as "in correspondence with human ideals." 

I am so little convinced of the existence of any dis- 
position of nature to transform our ills into goods, and 
our disharmonies into harmonies, that it would not surprise 
me if such an ideal were never reached. Even in unmeta- 
physical circles it is said that nature has the intention of 
preserving the species at the expense of the individual. The 
ground of this is that the species survives the individual . On 
the other hand, very many species have completely disap- 
peared. Amongst these species were animals very highly 
organised, such as some anthropoid apes (Dryopithecus, 
etc.). As nature has not spared these, how can we be 
certain that she is not ready to deal with the human race 
in the same way. It is impossible for us to know the un- 
known, its plans and motives. We must leave nature on 
one side and concern ourselves with what is more congru- 
ous with our intelligence. 

Our intelligence informs us that man is capable of much, 
and for this reason we hope that he may be able to modify 
his own nature and transform his disharmonies into har- 
monies. It is only human will that can attain this ideal. 



Abraham, use of soured milk, 171 

Ackermann, Mde., 237 

Actinosphcerium, degeneration in, 14 

Adanson, on age of Baobab-tree, 98 

Adrenaline, effect of, 121 

Agave, duration of life of, 100 

Aged, treatment of in uncivilised 
countries, i, a 

Alcohol and longevity, 91, 92 

Algeria, ostriches at, 76, 78, 79 

Altruism, 331 

Ambard, Dr., on Mde. Robineau, 7 

Anaemia, of brain, and sleep, 122 
use of serums in, 149 

Andre, M., use of serums in 
anasmia, 149 

Anger, 321 

Annandale, Nelson, on age of ane- 
mones, 48 

Annuals, change to biennials or 

perennials, 100 
death of, 102 

Antelopes, excreta of, 66 

Anthropoids, mental characters of, 
191 ct seq. 

Antiseptics, use of, in intestinal 
putrefaction, 156 

Ants, 220, 221 

Apes, anthropoid, mental characters 

of, 191 et seq. 
relationship to man, 184, 185 

Arabs, use of milk by, 174 

Aristotle, 132 

Arteries, sclerosis of, in the aged, 

3 1 

Ascidians, social, 219 
Ashworth, Mr., on age of anemones, 


Atheroma, in the aged, 30 
Atrophy, of cells, 26 
of muscles, 28 

Auditory apparatus, rudimentary 

organism, 188 

Augsburg, elixir of life, 138 
Auto-intoxication, from intestinal 

putrefaction, 69 
in plants, 107 
sleep, due to, 120 

Babinsky, Dr., hysteria a relic 
from apes, 209 

Balkan States, centenarians fre- 
quent in, 90 

Baobab-tree, age of, 98 

Barth, Dr., definition of somnam- 
bulism, 206 

Batrachia, longevity of, 50 

Bats, intestinal flora of, 80, 81 

Bees, 49, 220, 226 

Beetroot, perennial variety of, 100 

Belgium, old age pensions, 4 

Belonovsky, M., on serums in 
anaemia, 148 

Belonowsky, Dr., on Bulgarian 
bacillus, 170 

Berthelot, on dragon-tree of Oro- 
tava, 96 

Bertrand, M. G., on sorbose fer- 
mentation, 106 

Bertrand and Weisweiler, on Bacil- 
lus bulgaris, 179 

Besredka, M., on blood serums, 
148, 149 

Bielschowsky, biographer of Goethe, 

Blanchard, E., on age of carp, 50 

Birds, intestinal flora of, 76, 79 
longevity of, 52 

Blindness, 248, 257 

Bloch, Dr. I., on Schopenhauer, 
2 47 



Blood-vessels, hardening of, in the 

old, 31 

Bodio, on infant mortality, 85 
Boerhave, on gerokomy, 136 
Bones, degeneration of, 29, 30 
Bordet, M. J. M., on serums, 148 
Botulism, poison of, 70, 82 
Bouchard, M., on disinfection of 

intestines, 156 
Bouchet, M., on constipation after 

parturition, 68 

Bourneville, M., on effects of extir- 
pation of thyroid, 34 
Boveri, M., produced atherana by 

nicotine, 32 

Bone, marrow, in old age, 37 
Botryllus, 219 
Boutroux, definition of morality, 

Bradyfagy, 159 

Brain, anaemia of, as cause of 
sleep, 122 

Brehm, on age of cattle, 55 

Brettes, criticism of " rudimentary 
organs," 186 

Bricon, M., on effects of extirpa- 
tion of thyroid, 34 

Brigand, Calabrian, fear of death, 

'94. *95 

Brillat-Savarin, quotation from, 126 
Brown-S^quard, specific for long 

life, 139, 277 
Brudzinsky, M., on use of lactic 

microbes, 181 

Buddha, on pessimism, 233, 247 
Buehler, Dr., on cause of old age, 


Buffon, on duration of life, 40, 50 
Bulgarian bacillus, 178, 179, 180, 

iSi, 182 
Bunge, on relation between growth 

and longevity, 42 
Burbank, American horticulturist, 

326, 328 

Butterflies, longevity of, 57 
Butschli, O., on life of cells, 15 
Byron, 239, 247, 295 

C.ACHEXIA, after extirpation of 

thyroid gland, 34 
Caeca, of vertebrates, 60 et seq. 
Cagliostro, elixir of life, 138 
Calomel, as an intestinal antiseptic, 

syphilis, 146 
Camphor, as an intestinal anti- 
septic, 156 

Canary Islands, 96 

Cancalon, Dr., on instinct of death, 

128, 129 

Cancer, and cleanliness, 144 
Candolle, A. de, on cypresses of 

Mexico, 98 
on age of trees, 99 
Cantacuzene, M., on blood serums 


Capital punishment, 305 
Carlyle, on " Werther," 265 
Castration, effects of, 272 
Cats, longevity of, 56 
Cattle, longevity of, 55 
Celibacy, and education of women, 


Cell reproduction, rate of, 16 
Centenarians, 4, 5, 86, 88, 89, 175, 

Charcot, on sterilised food, 162, 163 

on hysteria, 202 
Charron, M., on putrefactive 

poisons, 69 
Chemin, M., on centenarians, 88, 


Chimpanzee, 185, 192, 193 
China, Emperor Chi-Hoang-Ti and 

immortality, 137 
Chopin, a degenerate, 134 
Christian morality, 321, 330 
Chromophags, action of, 25 
Claparede, E., on theory of sleep, 

123, 124, 125 
Cleanliness, and increase of life, 

Clergymen, increasing duration of 

life of, 142 

Coffee and longevity, 92 
Cohausen, on gerokomy, 137 
Cohendy, Dr. M., on Bulgarian 

bacillus, 178 

on intestinal flora, 78, 79 
on intestinal putrefaction, 168 
on thymol as a disinfectant, 157 
Collectivism, 228 
Colon, absorption in, 64 
Constipation, evil results of, 67, 

68, 69 
Cooking, effect of, on microbes in 

food, 162 

Copenhagen, suicide in, 3 
Coral polyps, 216 
Cornaro, 91 

Cossacks, and biennial rye, 100 
Cretinism, compared with senility, 


Croesus, 197 
Cryptogams, life of, 99 



Cursorial birds, intestinal flora of, 


Cypress, age of, 98 
Czerny, M., on absorption in 

colon, 64 
on cancer, 144 

D 'ALTON, and Goethe, 280 
Dalyell, old anemone of, 48 
Dana, on monstrilla, 115 
Darwin, on fear, 195 
David, King, 136 
Death, instinct of, 128, 129 
natural, 94, 109, 119 
sensations at approach of, 126, 

127, 130 
Debreuil, Ch., on defecation in 

rheas, 76 

on excreta of antelopes, 66 
Degenerates, famous, 134 
Delage, Yves, criticism of instinct 

of death, 128 
on function of large intestines, 

65, 66 

Demange, M., on old age, 119 
Denmark, suicide in, 3, 237 
Descent of man, 184 
Despotism, and socialism, 230 
de Vries, H., on duration of life 

of plants, 104 
on prolongation of life of 

plants, 100 

on natural death in plants, 101 
Diet and longevity, 46 
Digestive system and senility, 59 
Diplogaster, mother killed by 

larvae, in 
Diphtheria, 323 
Disease, and shortening of life, 145 

et seq. 

Doctors, lady, 225 
Dodo, 213 

Dogs, longevity of, 55 
Dostoiewsky, quotation from, 2 
Doyen, M., operation on double 

monsters, 216 

Dragon-tree, of Orotava, 96, 97, 98 
Drakenberg, age of, 87 
Drunkenness, and morality, 317 
Dryopithecus, 334 
Ducks, old, ii 
Duering, on pessimism, 248 
Durand-Fardel, M., on atheroma, 


Duration of life, in animals, 39 et 
seq., 133 

EAGLES, intestinal flora of, 82 
Ecclesiastes, quotation from, 233 
Eckermann, narrative of Goethe's 

last years, 271, 274, 279 
Egoism, 227, 306, 331 
Egyptian milk, 105 
Eimer, Th., on intestines of bats 

&c., 62, 63 

Einhorn, Dr., on bradyfagy, 159 
Elective Affinities, Goethe's, 273 
Elephants, 9, 54, 83, 197 
Eliot, George, 322 
Elixir vitce, 138 
Ellenberger, on digestion in horse, 


Enriquez, on infusoria, 13 
Ephemeridae, duration of life of, 

113, 118 
Epicureans, 309 
Epiphyses of bones, as giving 

period of growth, 40 
Ermenghem, van, on botulism, 70 
Errera, Dr., on cause of sleep, 121 
Eudoxia, 218 

Ewald, on absorption in colon, 64 
Exhaustion, as cause of plant 

death, 104, 107 
Extinction of animals, 213 
Eye, in old age, 36 

FATIGUE, Weichardt on cause of, 


" Faust " and Goethe, 283 et seq. 
Favorsky, Dr., on botulism, 82 
Fear, analysis of, 194 
Fecundity and duration of life, 43, 

44. 45. 57. 58 
Feinkind, case of somnambulism 

quoted from, 204 
Femininist movement, 224 
Fermentation, cause of, 105 
Fertility and longevity, 44, 45 
Fish, longevity of, 50 
Flamans, M., 5 
Fletcher, on chewing, 159 
Flora, of intestines, poisonous 

effect of, 70, 73 et seq., 151 et 

Flourens, on duration of life, 40, 

Foa, on use of soured milk in 

Africa, 172 
Food, evil effects of putrefaction 

in, 163 

Fouard, M., on soured milk, 180 
Fiirbbinger, on Brown-Se"quard's 

emulsions, 139 




Gautier, A., on leucomaines, 121 
Gegenbaur, on intestinal tract, 60, 


Genius and sexual power, 272 
Gerokomy, 136 
Gessner, on age of pike, 50 
Gestation and longevity, 42 
Giacomini, on Harderian gland, 189 
Gibbons, 192, 198 
Goebel, on duration of life of 

protnalli, 101, 102 
Goethe, 260-300, 305 
" Goose-skin," 196 
Gorilla, strength of, 192 
Griesbach, on sense of touch in 

blind, 257 
Grigoroff, on Bulgarian yahourth, 

175, 178 

Grindon, on age of sheep, 55 
Guinon, Dr., on a case of hysteria, 

Gurney, J. H., on longevity of 

birds, 51, 79 

HAECKEL, on medical selection, 134 

Haffkine, M., 112 

Hair, 17, 18 

Halictus, a solitary bee, 226 

Haller, on human longevity, 84, 


Hamlet, quotation from, 239 
Hannibal, his elephants swim the 

Rhone, 197 
Harderian gland, 189 
Hartmann, 235, 241 
Harvey, on Parr, 87 
Hayem, Prof., on use of lactic 

acid, 169, 173 
Heart, diseases of, and syphilis, 

MS. 146 

Hegesias, and suicide, 234 
Heile, on absorption in colon, 64 
Heim, on microbes in milk, 176 
Heim, Prof., on Alpine accidents, 


Heine, 236, 240 

Hermippus, and gerokomy, 137 
Herter, Dr., experiments on lactic 

acid in dogs, 167 
Hertwig, R., on Actinosph&rium, 

Hildebrand, on duration of life of 

plants, 101, 102 
Hippocrates, 132 
Hofmeister, on digestion in horse, 

Honey-ant, 222 

Horse, caecum, 62 
digestion, 74 
use of serum, 147 
Horsley, Sir V., on effects of ex- 
tirpation of thyroid, 34 
Horst, on a somnambulistic soldier, 

Huf eland, quotation from " Macro- 

biotique," 137 

Hugo, V., and sexuality, 277 
Humboldt, on dragon-tree of Oro- 

tava, 96 

on longevity of parrots, 52 
Hunger, compared with sleep, 125 
Huxley, on character of Orang, 193 
Hygiene, and old age, 141, 142, 143 
Hypnotism, of a crowd on indi- 
viduals, 210 

Hysteria, analysis of, 200 et seq. 
in monkeys, 208 

IBSEN, and sexuality, 277 

Idleness, 316 

Immortality, Chinese beverage for, 

137. '38 
Incubation, duration of, compared 

with longevity, 41, 42 
India, government of, and age of 

elephants, 54 
Individualism, 316 
Individuality, 212 et seq. 
Infusoria, death of, 95 

senescence of, 13 
Insects, ages of, 49 

social, 220 et seq. 
Instinct, of death, 128, 129 
maternal, 319, 320, 329 
social, 306 

Intestine, large, 59, 65, 67, 151 
Intuitive theory of morality, 305 

JACOBSON, organ of, 187 

Javal, Dr., on characters of the 

blind, 257, 259 
Jenner, effect of vaccination on 

mortality rate, 144 
Josue, M., artificial production of 

atheroma, 32 

Jousset, Dr., on difference between 
man and apes, 184 

KANT, 309, 310 

Kautsky, on socialism, 229, 230 

Kentigern, age of, 87 



Kephir, 171, 172, 173 

Khoury, M., on ferment of Egyp- 
tian milk, 105 

Kocher, Dr., on effects of extirpa- 
tion of thyroid gland, 33 

Kocher, Prof., case of removal of 
large intestine, 152, 153 

Kolliker, on degeneration of 
muscles, 27 

Koppenfels, on character of gorilla, 

Koumiss, 172 

Kowalevsky, Sophie, 225 

Kowalevsky, analysis of pessimism, 

24 1 . 2 55 
Kukula, experiments on intestinal 

poisons, 69, 70 
Kwass, 166 

LACTIC BACILLI, and putrefaction in 

intestine, 168 
Laignel-Lavastine, M., criticism of 

neuronophagy, 20 

Lankester, Sir E. Ray, on lon- 
gevity, 12, 56 

Lao-Tse", and immortality, 137 
Laud, Archbishop, old tortoise of, 

Lautschenberger, on absorption in 

colon, 64 

Lavater, Goethe's letter to, 268 
Laws aiding the aged, 3, 4 
" Leben," Egyptian, 105, 171, 177, 

Le Bon, G., on hysteria in crowds, 


Lenau, M., 236 
Lenthe'ric, on elephants swimming, 

Leopard!, G., pessimistic poet, 235, 

. 236, 247 
Le Play, M., on putrefactive 

poisons, 69 

LeVi, M., on senile brain, 20 
Lermontoff, 236 

Leucomaines, as cause of sleep, 121 
Levaillant, on longevity of parrots, 

S 2 
Lewes, G. H., on Goethe, 273, 290, 

29;, 298 
Lexis, on duration of human life, 

Life, duration of, in animals, 39 

et seq. 
Life, prolongation of human, 132, et 

" sense " of, 260 

Lima, Dr., on use of soured milk 

in Africa, 172, 174 
Lloyd, M., old anemone of, 47 
London Zoological Gardens, 51, 81 
Longevity, in animal kingdom, 47 

et seq. 

human, 84 et seq. 
rules for, 141 
in sexes, 44 
theories of, 39 
Lorand, Dr., on ductless glands, 


Love, Goethe and, 272 
Loewenberg, Dr., on Mde. Robin- 

eau, 7 
Luxury, 321 

MACFADYEN, Nencki and Mde. 

Sieber, on digestion, 153, 161 
Macrophags, 25, 147 
Mailaender, 235, 255 
Malaquin, M., on Monstrilla, 116, 


Male rotifers, death of, 114, 115 
Malthus, theory of, 214 
Mammals, longevity of, 53 
Mammary glands, in males, 186 
Man, compared with apes, 184, 185 
natural death of, 119 et seq. 
longevity of, 84 et seq. 
Manouelian, M., on neuronophagy, 

21, 22 

Marinesco, M., on neuronophogs, 

Marrow of the bones, in old age 

Marsiliaceae, duration of life of 

prothallus, 99 
Martin, on Gibbons, 192 
Massart, on cause of death in 

plants, 102, 109 
Massol, Prof., 178 
Mastication, and intestinal putre- 
faction, 1 60 
Matchinsky, M., on atrophy of 

ovary, 26 

Maternal instinct, 319, 320 
Mauclaire, M., operations on large 

intestine, 153, 154, 155 
Maumus, M., on digestion in caeca, 


Mauritius, giant tortoise from, 12 
Maupas, M., on infusoria, 13 
Maya, 178 

Mayers, on Chinese elixir, 138 
Meconium, appearance of microbes 

in, 161 



Medical selection, 134 

Mesnet and Mottet, Drs., cases of 

hysteria, 203 

Mice, duration of life, 41, 43, 56 
Michaelis, on muscles of monkeys, 


Microbes, as cause of senility, 73 
in food, 162, 163 
passage through intestinal 

walls, 71 

Middlemarch, G. Eliot's, 322 
Milk, importance of boiling, 177, 


microbes of disease in, 177 
putrefaction and fermentation 

of, 167 

use of soured milk, 181, 182 
Mill, J. S., 323 
Milne-Edwards, H., on laws of 

duration of life, 42 
Minot, Prof., on cause of old age, 

1 6 

Moa, 213 

Moebius, on Goethe, 271 
on Schopenhauer, 255 
Molluscs, ages of, 48 
Mongols, hair in old, 17 
Monkeys, longevity of, 83 
Monsters, double, 216 
Monstrilla, life-history of, 115, 116, 


Montefiore, Sir M., 91 
Morality, Christian, 321 
definitions of, 303 
Kantian, 309, 310, 311, 312 
science and, 301 et seq. 
Mortality rates of old persons, 142, 


Moses, use of soured milk, 171 
Mosso, on fear, 194, 196 
Muscles, degeneration of, 9, 26, 27 
Myxomycetes, 215 

NAEGELI, on age of trees, 99 

Nails, growth of, in the old, 18 

Naphthaline, as an intestinal anti- 
septic, 156 

Nature, human, 325 

Nausenne, Mde., cause of longevity, 

Negroes, longevity of, 88 

Neisser, Prof., on protection 
against syphilis, 146 

Nematodes, death of, in 

Nemertines, life-history of Pilidium 
of, 109 et seq. 

Nencki and Sieber, on digestion, 
153, 161, 169 

Neuronophags, 19, 20, 21, 22, 23, 

Nicotine, use of in experimental 

production of atheroma, 32 
Nietzsche, criticism of Socialism, -230 
Nogueira, M., on use of soured milk 

in Africa, 172, 174 

OBSTACLES, sense of, 258 
Old age, Goethe and, 279 et seq. 
Olympian, Goethe as an, 269 
Optimism, foundation of, 256 

Goethe's transformation to, 

269, 270 et seq. 
Orang-outan, 185, 193 
Orotava, dragon-tree of, 96 
Orstein, Dr., on centenarians ill 

Greece, 90 

Orthobiosis, 212, 325 et seq. 
Ossetes, use of soured milk, 173 
Osteoclasts, 30 
Ostrich, defecation of, 76 
Oustalet, M., on longevity of verte- 
brates, 46 

Ovary, atrophy of, 26 
Owls, intestinal flora of, 83 
Ownership, collective, 229, 230 

PARODI, on old age, 332 

Parr, Thomas, 87 

Parrots, duration of life, 41 

scanty intestinal flora of, 79 
Pasquier, Dr. du, on constipation, 

Pasteur, discovery of lactic microbe, 

105, 167 

Paulsen, criticism of Kant, 314 
Pensions, old age, 3, 4, 133 
Pessimism, 129, 233, 234, 239, 241, 

249, 266 
Pessimist, study of life-history of a, 

249 et seq. 

Pfliiger, on longevity, 93 
Phagocytes, 18, 19 
Phagocytosis, examples of, 25, 37 
Phalansteries, 229 
Pilidium, 109 et seq. 
Pitres, M., hysteric patients of, 200 
Plague, 323 

Plants, death of, 99, 103 
Plasmodia, of Myxomycetes, 215, 


Pleurotrocha haffkini, 112, 113 
Pochon, Dr., experiments on use of 

lactic bacilli, 169 
Poehl, Dr., on spermine, 139, 140 
Pohl, Dr., on growth of hair, 17, 18 
Pono genes, as cause of sleep, 120 


Potatoes, improved by Burbank, 326 

Poushkin, 236 

Predestination, and plants, 103 

Preyer, Dr., on Ponogenes, 120 

Prichard, on longevity of negroes, 

Productivity compared with fecund- 
ity, 57. 58 

Prostokwacha, 172, 176 

Prolongation of life, 132 et seq. 

Prothalli, life of, 99 

Psychids, death of, 117 

Ptolemy, fear of Hegesias' philo- 
sophy, 235 

Punishment, capital, 305 

Purgatives, use of, in intestinal 
putrefaction, 157 

Putrefaction, intestinal, 151 et seq., 
161, 163, 164 

QUETELET, on stature of the aged, 9 

RABBIT, fecundity of, 58 

Ravens, absence of putrefaction in 

intestines of, 75" 
Reagents, action of, in distorting 

tissues, 20 
Renouvier, C., on his own death, 

Reproduction, organs of, rudiments 

in, 189 

Reptiles, longevity of, 50 
Rhea, caeca of, 60, 77 
Rhinoceros, longevity of, 54 
Rhytina, 213 

Riley, James, on food of Arabs, 174 
Rimpau, on cultivation of rye, 326, 


Rist and Khoury, on milk, 178 
Rist, M., on ferment of Egyptian 

milk, 105 
Riviere, M., on defecation in 

ostriches, 76, 78, 79 
Robineau, Mde., 5, 6, 7, 8, 128, 159 
" Roman Elegies," Goethe's, 268, 

Rotifera, duration of life, 39 

death of, 112 

Roux, anti-syphilitic ointment, 146 
Rovighi, on Kephir, 173 
Rudimentary organs, 185 et seq. 
Rye, duration of life of, 100 

Rimpau 's improvement of, 326 
Salpe^riere, hysterical patients at, 

old women in the, 4, 5 

Sand, M., on senile brain, 20 
Sargent, on age of Sequoia, 98 
Sauer-kraut, 165, 171 
Sauvage, M., on atheroma, 30 
Savage, on character of anthro- 
poids, 193 
Saxe-Weimar, Grand Duke of, and 

Goethe, 274 

Schaudinn, spirillum of syphilis, 31 
Schiller, Goethe on, 271 
Schiller, on moral conduct, 310 
Schlanstedt, rye of, 326 
Schmidt, on microbes in constipa- 
tion, 70 
Schopenhauer, 235, 247, 255, 277, 


Schumann, a degenerate, 134 
Science, and morality, 301 et seq. 
Sclerosis, in the aged, 31 
Sea-anemones, longevity of, 47, 48 
Sea-cow, 213 
Selection, medical, 134 
Seneca, 132, 235 

Senescence, Brown-S^quard's speci- 
fic against, 139 
mechanism of, 25 
phagocytosis as cause of, 35 
Senility, characters of, 8, 14 
and digestive system, 59 
theories of causation of, 15 et 

Sensation, analysis of, with regard 

to pain and pleasure, 243 
Sense of life, 26 

of obstacles, 258 
Sense. organs of, rudimentary 

structures in, 186, 187 
"Sermon on the Mount," 321 
Serums, cytotoxic, 147, 148, 149 
Servants, care of, 321 
Sex, and longevity, 57 
Sexuality, Goethe and, 273 et seq. 
and old age, 276 
moral problems of, 305 
Sexual organs, abnormalities of, 224 
Sexual power and genius, 272 
Shakespeare, quotations, 239, 307 
Sheep, digestion of, 74 

longevity, 55 

Sight, rudimentary organs of, 189 
Silos, 165 
Siphonophora, 217 
Skeleton, atrophy of, in the aged, 


Sleep, and anaemia of brain, 121 
and auto-intoxication, 120 
and death compared, 125 



Sleepiness, compared with hunger, 

I2 5 

Sleeping-sickness, 124 
Small-pox, and mortality rates, 144 
Smell, analysis of, 243 
Smell, rudimentary organs of sense 
__ of, 187 

Smoking and longevity, 93 
1 Social animals, 214, 220 et seq. 
Socialism, 228, 229 

Tavel, M., operations on large in- 

testine, 152 et seq. 
Taylor, Bayard, translation of 

Faust, 285 
Termites, 220, 221 
Testis, emulsion of, as used by 

Brown-Se'quard, 139 
resistance of, to senescence, 35 
Thanatology, 131 
Theophrastus, 132 

Society v. the individual, 223 et seq. Thymol, as an intestinal antiseptic, 
Society, and morality, 306 157 

Thyroid, effects of extirpation of, 

Sociology, dependent on biology, 231 
Sollier, Dr., on sensations at death, 

Solomon, quotation from " Eccle- 

siastes," 233 
Somnambulism, analysis of, 200 et 


Sorbose, fermentation of, 106 
Soured milk, use of, 171, 181, 182 
Sparrow, fecundity of, 58 
Spencer, Herbert, criticism of Kant, 


criticism of socialism, 230 
theory of morality, 316, 322, 

324, 327 

Spermatozoa, in old age, 35 
Spermine, 139, 140 
Stadelmann, on lactic acid in dia- 

betes, 170 

Statistics on suicide, 3 
Stature, in old age, 8, 9 
Stein, Mde. von, 267, 268, 273 
Steller's sea-cow, 213 
Stern, M., on disinfection of intes- 

tine, 156 

32, 33, 34 
Timon of Athens, quotation from, 

Tissier, Dr., on Bacillus bifidus, 161 

on use of lactic microbes, 181 
Tissier, and Martelly, on putrid 

food, 164 

Tobacco and longevity, 93 
Tokarsky, on natural death, 126 
Tolstoi, and death, 94 

" Death of Ivan Ilyitch," 318 
Tortoise, n, 12, 13, 51 
Touch, sense of, in the blind, 257 
Troubat, M., on instinctive swim- 

ming, 198 

Trees, age and death of, 96, 97, 98 
Trypanosoma, 124 

UNICELLULAR organisms, death of, 

Urine, analysis of, in a centen- 

arian, 7 
Utilitarianism, 305 

Stohmann, on digestion in sheep, 74 VACHEROT, criticism of Kant, 313 
Stoics, 309 
Stragesco, Dr., on digestion in 

mammals, 63 

Strasburger, on disinfection of in- 
testine, 156, 157 
on microbes in constipation, 70 
Suicide, 3, 4, 237, 238, 265, 311 
Sully-Prudhomme, definition of 

morality, 303 
Suprarenal capsules, and atheroma, 

3 2 
Swimming, instinctive power of, 

197, 198, 207 

Syphilis, 31, 37, 145, 146, 302, 304 
Switzerland, centenarians rare in, 91 

TANACOL, as an intestinal antiseptic, 


Taoism and immortality, 137, 138 
Taste, analysis of, 243 

Varenetz, 172 

Vascular glands, relation to old 

age, 33- 34 
Verworn, Max, on death in in- 

fusoria, 95 
Vinegar, in preservation of food, 


Vivisection, 301 
Voisin, M., criticism of neurono- 

phagy, 20 
Voltaire, 92, 235 
Volz, on swimming power of gib- 

bons, 198 

WALES, Mr., quotation from Riley, 

Weber, Dr., on regimen for old 

age, 140, 141 
Weichardt, on cause of fatigue, 

122, 123 



Weinberg, Dr., on preparation of 

human serums, 150 
on thyroid gland in aged, 33 
Weiske, on digestion in sheep, 78 
Weismann, A., on cause of old age, 

15, 16 

on death in infusoria, 95 
on duration of life, 41, 43, 45, 

" Weltschmerz, " in German poetry, 


Werther, Goethe's, 263, 267 
Westergaard, statistics of mor- 
tality, 142, 144 

Wiedersheim, on intestinal tract, 60 
Wine, Goethe and, 271, 279 

Wolff, J. H., Goethe's friend, 271 
Women, education, 224 et seq. 

YAHOURTH, use in intestinal putre- 
faction, 168, 170, 175, 177, 178 
Yeast, conditions of growth, 106 

ZEIGAN, Dr., on adrenaline, 122 
Zell, Dr., on blind persons, 259 
Zelter, Goethe's friend, 265 
Zola, " La Joie de Vivre," 248 
Zoological Gardens of London, 51, 

Zortay, Pierre, age of, 87 



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